#!/usr/bin/perl
# NAME: xp2csv.pl
# AIM: Read X-Plane (Robin Pell) earth_nav.dat and apt.dat, and output as CSV and json to 
# a target directory
# 2018-02-26 - Review and update
# 07/12/2013 - remove navaids (and ils) from json output
# geoff mclane - http://geoffmclane.com/mperl/index.htm - 20100801
use strict;
use warnings;
use File::Copy;
use Math::Trig;
use File::Basename;  # split path ($name,$dir,$ext) = fileparse($file [, qr/\.[^.]*/] )
use Time::HiRes qw( gettimeofday tv_interval );
my $os = $^O;
my $perl_dir = $0;  # '/home/geoff/bin';
$perl_dir =~ s/xp2csv\.pl$//;
$perl_dir = '.' if (length($perl_dir) == 0);
##my $perl_dir = '/home/geoff/bin';
my $PATH_SEP = '/';
my $temp_dir = '/tmp';
if ($os =~ /win/i) {
    #$perl_dir = 'C:\GTools\perl';
    $temp_dir = $perl_dir;
    $PATH_SEP = "\\";
}
unshift(@INC, $perl_dir);
require 'lib_utils.pl' or die "Unable to load 'lib_utils.pl' Check paths in \@INC...\n";
require 'fg_wsg84.pl' or die "Unable to load fg_wsg84.pl ...\n";
#require "Bucket2.pm" or die "Unable to load Bucket2.pm ...\n";
require "Bucket.pm" or die "Unable to load Bucket.pm ...\n";

# =============================================================================
# This NEEDS to be adjusted to YOUR particular default location of these files.
my $FGROOT = "D:/FG/xplane/1000";
###my $FGROOT = "D:/SAVES/xplane";
my $APT_FILE 	= "$FGROOT/apt.dat";	# the airports data file
###my $APT_FILE   = "$FGROOT/apt4.dat";	# the airports data file
my $NAV_FILE 	= "$FGROOT/earth_nav.dat";	# the NAV, NDB, etc. data file
my $FIX_FILE    = "$FGROOT/earth_fix.dat";	# the FIX data file
my $LIC_FILE    = "$FGROOT/AptNavGNULicence.txt";
# =============================================================================

my $VERS = "0.0.8 20180226";
###my $VERS = "0.0.7 20131207";
###my $VERS = "0.0.6 20131116";
###my $VERS = "0.0.5 20131111";

# log file stuff
our ($LF);
my $pgmname = $0;
if ($pgmname =~ /(\\|\/)/) {
    my @tmpsp = split(/(\\|\/)/,$pgmname);
    $pgmname = $tmpsp[-1];
}
my $outfile = $temp_dir.$PATH_SEP."temp.$pgmname.txt";
open_log($outfile);

my $t0 = [gettimeofday];

my $out_path = '';
my $add_navaids_array = 0;
my $add_ils_array = 0;

#my $dout_path = $temp_dir.$PATH_SEP."temp-apts6";
#my $dout_path = $temp_dir.$PATH_SEP."temp-apts5";
#my $dout_path = $temp_dir.$PATH_SEP."temp-apts4";
#my $dout_path = 'C:\FG\17\fgx-globe\apt1000';
#my $dout_path = $temp_dir.$PATH_SEP."temp-apts2";
my $debug_on = 0;
##my $dout_path = $temp_dir.$PATH_SEP."temp-apts";
my $dout_path = 'F:\FG\apt-json';
my $show_first_6 = 0;

# program variables - set during running
# different searches -icao=LFPO, -latlon=1,2, or -name="airport name"
# KSFO San Francisco Intl (37.6208607739872,-122.381074803838)
my $aptdat = $APT_FILE;
my $navdat = $NAV_FILE;
my $licfil = $LIC_FILE;
my $fixdat = $FIX_FILE;
my $out_base = 'apt1000';
my $navdat2 = $temp_dir.$PATH_SEP."nav.dat";

# features and options
my $load_log = 0;
my $write_output = 1;   # write the CSV file
my $add_newline = 1;    # make json human readable
my $skip_done_files = 1; # do not overwrite previous json file

my $output_full_list = 1; # output ALL airports to ICAO.json
my $do_nav_filter = 1;
my $out_all_json = 1;

# CONSTANTS
# variables for range using distance calculation
my $PI = 3.1415926535897932384626433832795029;
my $D2R = $PI / 180;
my $R2D = 180 / $PI;
my $ERAD = 6378138.12;
my $DIST_FACTOR = $ERAD;
#/** Meters to Nautical Miles.  1 nm = 6076.11549 feet */
my $METER_TO_NM = 0.0005399568034557235;
#/** Nautical Miles to Meters */
my $NM_TO_METER = 1852;

my ($file_version);

my $av_apt_lat = 0;	# later will be $tlat / $ac;
my $av_apt_lon = 0; # later $tlon / $ac;

# apt.dat CODES - see http://x-plane.org/home/robinp/Apt850.htm for DETAILS
#my $aln =     '1';	# airport line
#my $rln =    '10';	# runways/taxiways line 810 OLD CODE
#my $sealn =  '16'; # Seaplane base header data.
#my $heliln = '17'; # Heliport header data.  

#my $rln =    '100';	# land runways
#my $water =  '101'; # Water runway
#my $heli =   '102'; # Helipad

# offsets into land runway array
#my $of_lat1 = 9;
#my $of_lon1 = 10;
#my $of_lat2 = 18;
#my $of_lon2 = 19;

my $twrln =  '14'; # Tower view location. 
my $rampln = '15'; # Ramp startup position(s) 
my $bcnln =  '18'; # Airport light beacons  
my $wsln =   '19'; # windsock
my $minatc = '50';
my $twrfrq = '54';	# like 12210 TWR
my $appfrq = '55';  # like 11970 ROTTERDAM APP
my $maxatc = '56';
my $lastln = '99'; # end of file

# nav.dat.gz CODES
my $navNDB = '2';
my $navVOR = '3';
my $navILS = '4';
my $navLOC = '5';
my $navGS  = '6';
my $navOM  = '7';
my $navMM  = '8';
my $navIM  = '9';
my $navVDME = '12';
my $navNDME = '13';
my @navset = ($navNDB, $navVOR, $navILS, $navLOC, $navGS, $navOM, $navMM, $navIM, $navVDME, $navNDME);
my @navtypes = qw( NDB VOR ILS LOC GS OM NM IM VDME NDME );

my $maxnnlen = 4;
my $actnav = '';
my $line = '';
my $apt = '';
my $alat = 0;
my $alon = 0;
my $glat = 0;
my $glon = 0;
my $rlat = 0;
my $rlon = 0;
my $dlat = 0;
my $dlon = 0;
my $diff = 0;
my $rwycnt = 0;
my $icao = '';
my $name = '';
my @aptlist = ();
my @aptlist2 = ();
my @navlist = ();
my @navlist2 = ();
my $totaptcnt = 0;
my $acnt = 0;
my @lines = ();
my $cnt = 0;
my $loadlog = 0;
my $outcount = 0;
my @tilelist = ();

my @warnings = ();

my @files_written = ();
my $json_count = 0;
my $json_bytes = 0;

# debug tests
# ===================
my $test_name = 0;	# to TEST a NAME search
my $def_name = "hong kong";

my $test_ll = 0;	# to TEST a LAT,LON search
my $def_lat = 37.6;
my $def_lon = -122.4;

my $test_icao = 0;	# to TEST an ICAO search
my $def_icao = 'VHHH'; ## 'KHAF';  ## LFPO'; ## 'KSFO';

# debug
my $dbg1 = 0;	# show airport during finding ...
my $dbg2 = 0;	# show navaid during finding ...
my $dbg3 = 0;	# show count after finding
my $verb3 = 0;
my $dbg10 = 0;  # show EVERY airport
my $dbg11 = 0;  # prt( "$name $icao runways $rwycnt\n" ) if ($dbg11);
# ===================

### program variables
my $verbosity = 0;

sub VERB1() { return $verbosity >= 1; }
sub VERB2() { return $verbosity >= 2; }
sub VERB5() { return $verbosity >= 5; }
sub VERB9() { return $verbosity >= 9; }

sub show_warnings($) {
    my ($val) = @_;
    if (@warnings) {
        prt( "\nGot ".scalar @warnings." WARNINGS...\n" );
        foreach my $itm (@warnings) {
           prt("$itm\n");
        }
        prt("\n");
    } else {
        prt( "\nNo warnings issued.\n\n" ) if (VERB9());
    }
}

sub pgm_exit($$) {
    my ($val,$msg) = @_;
    if (length($msg)) {
        $msg .= "\n" if (!($msg =~ /\n$/));
        prt($msg);
    }
    show_warnings($val);
    close_log($outfile,$load_log);
    exit($val);
}


sub prtw($) {
   my ($tx) = shift;
   $tx =~ s/\n$//;
   prt("$tx\n");
   push(@warnings,$tx);
}


########################################################################
### SUBS
#/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
#/* Vincenty Inverse Solution of Geodesics on the Ellipsoid (c) Chris Veness 2002-2012             */
#/*                                                                                                */
#/* from: Vincenty inverse formula - T Vincenty, "Direct and Inverse Solutions of Geodesics on the */
#/*       Ellipsoid with application of nested equations", Survey Review, vol XXII no 176, 1975    */
#/*       http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf                                             */
#/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
#
#/**
# * Calculates geodetic distance between two points specified by latitude/longitude using 
# * Vincenty inverse formula for ellipsoids
# *
# * @param   {Number} lat1, lon1: first point in decimal degrees
# * @param   {Number} lat2, lon2: second point in decimal degrees
# * @returns (Number} distance in metres between points
# */
use constant PI    => 4 * atan2(1, 1);

my $FG_PI = PI;
my $FG_D2R = $FG_PI / 180;
my $FG_R2D = 180 / $FG_PI;
my $FG_MIN = 2.22507e-308;
my $NaN = -sin(9**9**9);
sub toRad($) {
    my $deg = shift;
    return ($deg * $FG_D2R);
}
sub toDeg($) {
    my $rad = shift;
    return ($rad * $FG_R2D);
}

sub isNaN { ! defined( $_[0] <=> 9**9**9 ) }
# function distVincenty(lat1, lon1, lat2, lon2) {
sub distVincenty($$$$$$$) {
    my ($lat1, $lon1, $lat2, $lon2, $raz1, $raz2, $rs) = @_;
    my $a = 6378137;
    my $b = 6356752.314245;
    my $f = 1/298.257223563;  #// WGS-84 ellipsoid params
    my $L = toRad($lon2-$lon1); #.toRad();
    my $U1 = atan((1-$f) * tan(toRad($lat1)));
    my $U2 = atan((1-$f) * tan(toRad($lat2)));
    my $sinU1 = sin($U1);
    my $cosU1 = cos($U1);
    my $sinU2 = sin($U2);
    my $cosU2 = cos($U2);
    my $lambda = $L;
    my ($lambdaP);
    my $iterLimit = 100;
    my ($sinLambda,$cosLambda,$sinSigma,$cosSigma,$sigma);
    my ($sinAlpha,$cosSqAlpha,$cos2SigmaM,$C);
    do {

        $sinLambda = sin($lambda);
        $cosLambda = cos($lambda);
        $sinSigma = sqrt(($cosU2*$sinLambda) * ($cosU2*$sinLambda) + 
            ($cosU1*$sinU2-$sinU1*$cosU2*$cosLambda) * ($cosU1*$sinU2-$sinU1*$cosU2*$cosLambda));
        if ($sinSigma==0) { return 0; } # co-incident points
        $cosSigma = $sinU1*$sinU2 + $cosU1*$cosU2*$cosLambda;
        $sigma = atan2($sinSigma, $cosSigma);
        $sinAlpha = $cosU1 * $cosU2 * $sinLambda / $sinSigma;
        $cosSqAlpha = 1 - $sinAlpha*$sinAlpha;
        $cos2SigmaM = $cosSigma - 2*$sinU1*$sinU2/$cosSqAlpha;
        if (isNaN($cos2SigmaM)) { $cos2SigmaM = 0; } #// equatorial line: cosSqAlpha=0 (§6)
        $C = $f/16*$cosSqAlpha*(4+$f*(4-3*$cosSqAlpha));
        $lambdaP = $lambda;
        $lambda = $L + (1-$C) * $f * $sinAlpha *
            ($sigma + $C*$sinSigma*($cos2SigmaM+$C*$cosSigma*(-1+2*$cos2SigmaM*$cos2SigmaM)));

    } while (abs($lambda-$lambdaP) > 1e-12 && --$iterLimit>0);

    if ($iterLimit==0) { 
        prt("formula failed to converge!\n");
        return 1; # $NaN; #// formula failed to converge
    }
    my $uSq = $cosSqAlpha * ($a*$a - $b*$b) / ($b*$b);
    my $A = 1 + $uSq/16384*(4096+$uSq*(-768+$uSq*(320-175*$uSq)));
    my $B = $uSq/1024 * (256+$uSq*(-128+$uSq*(74-47*$uSq)));
    my $deltaSigma = $B*$sinSigma*($cos2SigmaM+$B/4*($cosSigma*(-1+2*$cos2SigmaM*$cos2SigmaM)-
        $B/6*$cos2SigmaM*(-3+4*$sinSigma*$sinSigma)*(-3+4*$cos2SigmaM*$cos2SigmaM)));
    my $s = $b*$A*($sigma-$deltaSigma);
  
    #  // note: to return initial/final bearings in addition to distance, use something like:
    my $fwdAz = atan2($cosU2*$sinLambda,  $cosU1*$sinU2-$sinU1*$cosU2*$cosLambda);
    my $revAz = atan2($cosU1*$sinLambda, -$sinU1*$cosU2+$cosU1*$sinU2*$cosLambda);
    # return { distance: s, initialBearing: fwdAz.toDeg(), finalBearing: revAz.toDeg() };
    ${$raz1} = toDeg($fwdAz);
    ${$raz2} = toDeg($revAz);
    # s = s.toFixed(3); // round to 1mm precision
    ${$rs} = (int($s * 1000) / 1000);
    return 0;
}

sub trimall($) {	# version 20061127
	my ($ln) = shift;
	chomp $ln;			# remove CR (\n)
	$ln =~ s/\r$//;		# remove LF (\r)
	$ln =~ s/\t/ /g;	# TAB(s) to a SPACE
	$ln =~ s/\s\s/ /g while ($ln =~ /\s\s/); # all double space to SINGLE
	$ln = substr($ln,1) while ($ln =~ /^\s/); # remove all LEADING space
	$ln = substr($ln,0, length($ln) - 1) while ($ln =~ /\s$/); # remove all TRAILING space
	return $ln;
}


sub get_tile { # $alon, $alat
	my ($lon, $lat) = @_;
	my $tile = 'e';
	if ($lon < 0) {
		$tile = 'w';
		$lon = -$lon;
	}
	my $ilon = int($lon / 10) * 10;
	if ($ilon < 10) {
		$tile .= "00$ilon";
	} elsif ($ilon < 100) {
		$tile .= "0$ilon";
	} else {
		$tile .= "$ilon"
	}
	if ($lat < 0) {
		$tile .= 's';
		$lat = -$lat;
	} else {
		$tile .= 'n';
	}
	my $ilat = int($lat / 10) * 10;
	if ($ilat < 10) {
		$tile .= "0$ilat";
	} elsif ($ilon < 100) {
		$tile .= "$ilat";
	} else {
		$tile .= "$ilat"
	}
	return $tile;
}

sub add_2_tiles {	# $tile
	my ($tl) = shift;
	if (@tilelist) {
		foreach my $t (@tilelist) {
			if ($t eq $tl) {
				return 0;
			}
		}
	}
	push(@tilelist, $tl);
	return 1;
}

sub is_valid_nav {
	my ($t) = shift;
    if ($t && length($t)) {
        my $txt = "$t";
        my $cnt = 0;
        foreach my $n (@navset) {
            $cnt++;
            if ($n eq $txt) {
                $actnav = $navtypes[$cnt];
                return $cnt;
            }
        }
    }
	return 0;
}

sub set_average_apt_latlon {
	my $ac = scalar @aptlist2;
	my $tlat = 0;
	my $tlon = 0;
	if ($ac) {
		for (my $i = 0; $i < $ac; $i++ ) {
			$alat = $aptlist2[$i][3];
			$alon = $aptlist2[$i][4];
			$tlat += $alat;
			$tlon += $alon;
		}
		$av_apt_lat = $tlat / $ac;
		$av_apt_lon = $tlon / $ac;
	}
}



sub set_apt_version($$) {
    my ($ra,$cnt) = @_;
    if ($cnt < 5) {
        prt("ERROR: Insufficient lines to be an apt.dat file!\n");
        exit(1);
    }
    my $line = trimall(${$ra}[0]);
    if ($line ne 'I') {
        prt("ERROR: File does NOT begin with an 'I'!\n");
        exit(1);
    }
    $line = trimall(${$ra}[1]);
    if ($line =~ /^(\d+)\s+Version\s+/i) {
        $file_version = $1;
        prt("Dealing with file version [$file_version]\n");
    } else {
        prt("ERROR: File does NOT begin with Version info!\n");
        exit(1);

    }
}

# sort by type
sub mycmp_ascend_n0 {
   return -1 if (${$a}[0] < ${$b}[0]);
   return  1 if (${$a}[0] > ${$b}[0]);
   return 0;
}


# sort by ICAO text
sub mycmp_ascend_t1 {
   return -1 if (${$a}[1] lt ${$b}[1]);
   return  1 if (${$a}[1] gt ${$b}[1]);
   return 0;
}

# sort by distance
sub mycmp_ascend_n1 {
   return -1 if (${$a}[1] < ${$b}[1]);
   return  1 if (${$a}[1] > ${$b}[1]);
   return 0;
}


# put least first
sub mycmp_ascend_n4 {
   if (${$a}[4] < ${$b}[4]) {
      return -1;
   }
   if (${$a}[4] > ${$b}[4]) {
      return 1;
   }
   return 0;
}

sub mycmp_ascend_n5 {
   if (${$a}[5] < ${$b}[5]) {
      return -1;
   }
   if (${$a}[5] > ${$b}[5]) {
      return 1;
   }
   return 0;
}

sub mycmp_ascend_n6 {
   if (${$a}[6] < ${$b}[6]) {
      return -1;
   }
   if (${$a}[6] > ${$b}[6]) {
      return 1;
   }
   return 0;
}

# put least first
sub mycmp_ascend {
   if (${$a}[0] < ${$b}[0]) {
      prt( "-[".${$a}[0]."] < [".${$b}[0]."]\n" ) if $verb3;
      return -1;
   }
   if (${$a}[0] > ${$b}[0]) {
      prt( "+[".${$a}[0]."] < [".${$b}[0]."]\n" ) if $verb3;
      return 1;
   }
   prt( "=[".${$a}[0]."] == [".${$b}[0]."]\n" ) if $verb3;
   return 0;
}

sub mycmp_decend {
   if (${$a}[0] < ${$b}[0]) {
      prt( "+[".${$a}[0]."] < [".${$b}[0]."]\n" ) if $verb3;
      return 1;
   }
   if (${$a}[0] > ${$b}[0]) {
      prt( "-[".${$a}[0]."] < [".${$b}[0]."]\n" ) if $verb3;
      return -1;
   }
   prt( "=[".${$a}[0]."] == [".${$b}[0]."]\n" ) if $verb3;
   return 0;
}

# sort by distance
sub mycmp_ascend_n11 {
   return -1 if (${$a}[11] < ${$b}[11]);
   return  1 if (${$a}[11] > ${$b}[11]);
   return 0;
}

sub fix_airport_name($) {
    my $name = shift;
    my @arr = split(/\s/,$name);
    my $nname = '';
    my $len;
    foreach $name (@arr) {
        $nname .= ' ' if (length($nname));
        $nname .= uc(substr($name,0,1));
        $len = length($name);
        if ($len > 1) {
            $nname .= lc(substr($name,1));
        }
    }
    return $nname;
}

sub in_world_range($$) {
    my ($lat,$lon) = @_;
    if (($lat <= 90)&&
        ($lat >= -90)&&
        ($lon <= 180)&&
        ($lon >= -180)) {
        return 1;
    }
    return 0;
}

# 20131108 - This is NOT sufficient, since it presently ONLY returns 4 == ILS
# But take LFPO example - just searching earth_nav.dat
# 4  48.73966100  002.38779200    291 11030  18      18.282 OLN  LFPO 02  ILS-cat-I
# 4  48.73638900  002.36332500    291 10850  18      61.794 ORE  LFPO 06  ILS-cat-III
# 4  48.71934400  002.31514200    291 11090  18     241.794 OLO  LFPO 24  ILS-cat-II
# 4  48.71863300  002.35440300    291 11175  18     254.372 OLW  LFPO 26  ILS-cat-III
# 5  48.72781100  002.40413300    291 10815  18      74.372 OLE  LFPO 08  LOC
# 6  48.71963300  002.38011700    319 11030  10  300018.282 OLN  LFPO 02  GS
# 6  48.72385600  002.32399200    291 10850  10  300061.794 ORE  LFPO 06  GS
# 6  48.73518900  002.35606900    291 11090  10  320241.794 OLO  LFPO 24  GS
# 6  48.72425800  002.39329400    291 11175  10  300254.372 OLW  LFPO 26  GS
# 7  48.65311100  002.34722200    291     0   0      18.282 ---- LFPO 02  OM
# 7  48.69073100  002.23407000    291     0   0      61.794 ---- LFPO 06  OM
# 7  48.76298100  002.43900000    291     0   0     241.794 ---- LFPO 24  OM
# 7  48.74282800  002.49154000    291     0   0     254.372 ---- LFPO 26  OM
# 12  48.72385000  002.32398100    291 10850  18       0.200 ORE  LFPO 06  DME-ILS
# 12  48.73518600  002.35606100    291 11090  18       0.200 OLO  LFPO 24  DME-ILS
# 12  48.72425800  002.39329400    291 11175  18       0.200 OLW  LFPO 26  DME-ILS

# grouping them per the runway they service, and excluding 'markers'
# 4   48.73966100  002.38779200    291 11030  18      18.282 OLN  LFPO 02  ILS-cat-I
# 6   48.71963300  002.38011700    319 11030  10  300018.282 OLN  LFPO 02  GS

# 4   48.73638900  002.36332500    291 10850  18      61.794 ORE  LFPO 06  ILS-cat-III
# 6   48.72385600  002.32399200    291 10850  10  300061.794 ORE  LFPO 06  GS
# 12  48.72385000  002.32398100    291 10850  18       0.200 ORE  LFPO 06  DME-ILS

# 4   48.71934400  002.31514200    291 11090  18     241.794 OLO  LFPO 24  ILS-cat-II
# 6   48.73518900  002.35606900    291 11090  10  320241.794 OLO  LFPO 24  GS
# 12  48.73518600  002.35606100    291 11090  18       0.200 OLO  LFPO 24  DME-ILS

# 4   48.71863300  002.35440300    291 11175  18     254.372 OLW  LFPO 26  ILS-cat-III
# 6   48.72425800  002.39329400    291 11175  10  300254.372 OLW  LFPO 26  GS
# 12  48.72425800  002.39329400    291 11175  18       0.200 OLW  LFPO 26  DME-ILS

# 5  48.72781100  002.40413300    291 10815  18      74.372 OLE  LFPO 08  LOC

sub find_ils_for_apt($) {
    my $find = shift;
    #                0     1     2     3     4     5    6     7   8     9    10
    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
    my $max = scalar @navlist;
    my ($i,$ra,$icao,$cnt,$type,$freq);
    $cnt = 0;
    my %freqs = ();
    for ($i = 0; $i < $max; $i++) {
        $ra = $navlist[$i];
        $icao = ${$ra}[8];
        next if ($icao ne $find);   # seeking only this ICAO
        $type = ${$ra}[0];  # get TYPE
        $freq = ${$ra}[4];
        ### next if ($type != 4); # 20130307 was 6, which is GS?
        # 20131108 - change to accept 4, 5 or 6, but filter on frequency
        if (($type == 4) || ($type == 5) || ($type == 6) || ($type == 12)) {
            if (! defined $freqs{$freq}) {
                $freqs{$freq} = 1;
                $cnt++;
            }
        }
    }
    return $cnt;
}

my %navaid_code = (
    2  => 'NDB',    # (Non-Directional Beacon) Includes NDB component of Locator Outer Markers (LOM)
    3  => 'VOR',    # (including VOR-DME and VORTACs) Includes VORs, VOR-DMEs and VORTACs
    4  => 'ILS',    # Localiser component of an ILS (Instrument Landing System)
    5  => 'LOC',    # Localiser component of a localiser-only approach Includes for LDAs and SDFs
    6  => 'GS',     # Glideslope component of an ILS Frequency shown is paired frequency, not the DME channel
    7  => 'OM',     # Outer markers (OM) for an ILS Includes outer maker component of LOMs
    8  => 'MM',     # Middle markers (MM) for an ILS
    9  => 'IM',     # Inner markers (IM) for an ILS
    12 => 'DME',    # including the DME component of an ILS, VORTAC or VOR-DME Frequency display suppressed on X-Plane’s charts
    13 => 'SDME'    # Stand-alone DME, or the DME component of an NDB-DME Frequency will displayed on X-Plane’s charts
);

# NOTE: This now get ALL navaid (earth_nav.dat) entries for this ICAO
sub get_ils_info($) {
    my $find = shift;
    my @arr = ();
    #                0     1     2     3     4     5    6     7   8     9    10
    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
    my $max = scalar @navlist;
    my ($i,$ra,$icao,$cnt,$type);
    $cnt = 0;
    for ($i = 0; $i < $max; $i++) {
        $ra = $navlist[$i];
        $type = ${$ra}[0];
        $icao = ${$ra}[8];
        ###next if ($type != 6); # WANT ALL TYPES with this ICAO
        if ($find eq $icao) {
            $cnt++;
            push(@arr,$ra);
            prt(join(",",@{$ra})."\n") if (VERB9());
        }
    }
    return \@arr;
}

my $min_nav_dist = 100;     # 100 nautical miles
my $pole_2_pole = 20014000; # m
my $min_nav_cnt = 10;
#  my $rnavs = get_nav_info($alat,$alon,$icao);
sub get_nav_info($$$) {
    my ($alat,$alon,$find) = @_;
    my @arr = ();
    my @dists = ();
    #                0     1     2     3     4     5    6     7   8     9    10
    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
    my $max = scalar @navlist;
    my ($i,$ra,$icao,$cnt,$type,$lat,$lon);
    my ($az1,$az2,$dist,$ret,$rd,$i2);
    my $mdist = $min_nav_dist * $NM_TO_METER;
    $cnt = 0;
    for ($i = 0; $i < $max; $i++) {
        $ra = $navlist[$i];
        $type = ${$ra}[0];
        $icao = ${$ra}[8];
        # WANT ALL TYPES without this ICAO, whihc was returned in get_ils_info
        # next if ($find eq $icao);
        next if (length($icao)); # ignore other airport ILS stuff
        $lat = ${$ra}[1];
        $lon = ${$ra}[2];
        $ret = fg_geo_inverse_wgs_84($alat, $alon, $lat, $lon, \$az1, \$az2, \$dist);
        if ($ret > 0) {
            $dist = $pole_2_pole; # make it BIG
            $az1 = 0;
        }
        push(@dists,[$i,$dist,$az1]);
        next if ($dist > $mdist);
        my @a = @{$ra};
        push(@a,(int($dist * $METER_TO_NM * 10) / 10));
        push(@a,(int($az1 * 10) / 10));
        push(@arr,\@a);
        $cnt++;
        prt("icao:$cnt: $find: ".join(",",@a)."\n") if (VERB9());
    }
    my @as = ();
    if ($cnt < $min_nav_cnt) {
        @dists = sort mycmp_ascend_n1 @dists;
        $cnt = 0;   # restart count
        for ($i = 0; $i < $max; $i++) {
            $rd = $dists[$i];
            $i2   = ${$rd}[0];
            $dist = ${$rd}[1];
            $az1 =  ${$rd}[2];
            $ra = $navlist[$i2];
            my @a = @{$ra};
            push(@a,(int($dist * $METER_TO_NM * 10) / 10));
            push(@a,(int($az1 * 10) / 10));
            push(@as,\@a);
            $cnt++;
            prt("icao:$cnt: $find: ".join(",",@a)."\n") if (VERB9());
            last if ($cnt >= $min_nav_cnt);
        }
    } else {
        @as = sort mycmp_ascend_n11 @arr;
    }
    return \@as;
}


#Runway line
##   0   1     2 3 4    5 6 7 8   9            10            11    12   13 14 15 16 17  18           19           20     21   22 23 24 25
#EG: 100 29.87 3 0 0.00 0 0 0 16  -24.20505300 151.89156100  0.00  0.00 1  0  0  0  34  -24.19732300 151.88585300 0.00   0.00 1  0  0  0
#OR: 100 29.87 1 0 0.15 0 2 1 13L 47.53801700  -122.30746100 73.15 0.00 2  0  0  1  31R 47.52919200 -122.30000000 110.95 0.00 2  0  0  1
#Land Runway
#0  - 100 - Row code for a land runway (the most common) 100
#1  - 29.87 - Width of runway in metres Two decimal places recommended. Must be >= 1.00
#2  - 3 - Code defining the surface type (concrete, asphalt, etc) Integer value for a Surface Type Code
#3  - 0 - Code defining a runway shoulder surface type 0=no shoulder, 1=asphalt shoulder, 2=concrete shoulder
#4  - 0.15 - Runway smoothness (not used by X-Plane yet) 0.00 (smooth) to 1.00 (very rough). Default is 0.25
#5  - 0 - Runway centre-line lights 0=no centerline lights, 1=centre line lights
#6  - 0 - Runway edge lighting (also implies threshold lights) 0=no edge lights, 2=medium intensity edge lights
#7  - 1 - Auto-generate distance-remaining signs (turn off if created manually) 0=no auto signs, 1=auto-generate signs
#The following fields are repeated for each end of the runway
#8  - 13L - Runway number (eg. 31R, 02). Leading zeros are required. Two to three characters. Valid suffixes: L, R or C (or blank)
#9  - 47.53801700 - Latitude of runway threshold (on runway centerline) in decimal degrees Eight decimal places supported
#10 - -122.30746100 - Longitude of runway threshold (on runway centerline) in decimal degrees Eight decimal places supported
#11 - 73.15 - Length of displaced threshold in metres (this is included in implied runway length) Two decimal places (metres). Default is 0.00
#12 - 0.00 - Length of overrun/blast-pad in metres (not included in implied runway length) Two decimal places (metres). Default is 0.00
#13 - 2 - Code for runway markings (Visual, non-precision, precision) Integer value for Runway Marking Code
#14 - 0 - Code for approach lighting for this runway end Integer value for Approach Lighting Code
#15 - 0 - Flag for runway touchdown zone (TDZ) lighting 0=no TDZ lighting, 1=TDZ lighting
#16 - 1 - Code for Runway End Identifier Lights (REIL) 0=no REIL, 1=omni-directional REIL, 2=unidirectional REIL
#17 - 31R
#18 - 47.52919200
#19 - -122.30000000
#20 - 110.95 
#21 - 0.00 
#22 - 2
#23 - 0
#24 - 0
#25 - 1

#Surface Type Code Surface type of runways or taxiways
#1 Asphalt
#2 Concrete
#3 Turf or grass
#4 Dirt (brown)
#5 Gravel (grey)
#12 Dry lakebed (eg. At KEDW) Example: KEDW (Edwards AFB)
#13 Water runways Nothing displayed
#14 Snow or ice Poor friction. Runway markings cannot be added.
#15 Transparent Hard surface, but no texture/markings (use in custom scenery)
# offset 2 in runway array
my %runway_surface = (
    1  => 'Asphalt',
    2  => 'Concrete',
    3  => 'Turf/grass',
    4  => 'Dirt',
    5  => 'Gravel',
    6  => 'H-Asphalt', # helepad (big 'H' in the middle).
    7  => 'H_Concrete', # helepad (big 'H' in the middle).
    8  => 'H_Turf', # helepad (big 'H' in the middle).
    9  => 'H_Dirt', # helepad (big 'H' in the middle). 
    10 => 'T_Asphalt', # taxiway - with yellow hold line across long axis (not available from WorldMaker).
    11 => 'T_Concrete', # taxiway - with yellow hold line across long axis (not available from WorldMaker).
    12 => 'Dry_Lakebed', # (eg. at KEDW Edwards AFB).
    13 => 'Water', # runways (marked with bobbing buoys) for seaplane/floatplane bases (available in X-Plane 7.0 and later). 
    14 => 'Snow',
    15 => 'Transparent'
);

my %frequency_code = (
    50 => "ATIS",   # 50 ATC – Recorded AWOS, ASOS or ATIS
    51 => "CTAF",   # 51 ATC – Unicom Unicom (US), CTAF (US), Radio (UK)
    52 => "CLD",    # 52 ATC – CLD Clearance Delivery
    53 => "GND",    # 53 ATC – GND Ground
    54 => "TWR",    # 54 ATC – TWR Tower
    55 => "APP",    # 55 ATC – APP Approach
    56 => "DEP"     # 56 ATC - DEP Departure
    );

sub output_apts_to_json($) {
    my $rapts = shift; # = \@sorted
    my $max = scalar @{$rapts};
    my ($i,$ra,$icao,$name,$alat,$alon,$rwycnt,$rwa,$ils,$line,$rfqa,$o_file,$base);
    my ($rcnt,$j,$rrwy,$i2,$j2);
    my ($wid,$surf,$code,$smth,$ctln,$elit);
    my ($rwy1,$lat1,$lon1,$rwy2,$lat2,$lon2);
    my ($rlen,$az1,$az2,$dist,$racnt,$type,$rha);
    my ($freq,$serv,$feet,$slope,$tmp,$rng,$rwwa,$elev);
    if ($max == 0) {
        prtw("WARNING: No airports to output!\n");
        return;
    }
    my $out_json = $out_path.$PATH_SEP.'json';
    if (! -d $out_json) {
        if (! mkdir($out_json)) {
            prtw("WARNING: Unable to create '$out_json'!\n");
            return;
        }
    }
    prt("Outputing JSON for $max airport(s)... to $out_json\n");
    my $bgntm = [gettimeofday];
    my ($elap,$lnspsec,$remain);
    # $line = "icao,name,lat,lon,runways,ils\n";
    $base = '{"success":true,"source":"'.$pgmname.'","last_updated":"'.
        lu_get_YYYYMMDD_hhmmss_UTC(time()).' UTC"';
    #                 1,16,17    ZZZZ          ws or average    watr           rwys freq cny   heli ELEV
    #                 0          1      2      3      4      5  6     7        8    9    10    11   12
    # push(@aptlist, [$lasttype, $icao, $name, $alat, $alon, 0, \@w,  $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
    for ($i = 0; $i < $max; $i++) {
        $i2 = $i + 1;
        $ra = ${$rapts}[$i];
        # added "type":'.$type;  # 1 land, 16 sea, 17 heli
        $type = ${$ra}[0]; # now all types 1 land, 16 sea, 17 heli
        $icao = ${$ra}[1];
        $name = fix_airport_name(${$ra}[2]);
        $alat = ${$ra}[3];
        $alon = ${$ra}[4];
        #$bucket = ${$ra}[5];
        $rwwa = ${$ra}[6];
        $rwycnt = ${$ra}[7];
        $rwa  = ${$ra}[8];
        $rfqa = ${$ra}[9];
        $ils  = ${$ra}[10];
        $rha  = ${$ra}[11];
        $elev = ${$ra}[12]; # 20140214 - *** ADD ELEVATION ***
        # generate the json FILE
        $o_file = $out_json.$PATH_SEP."$icao.json";
        if ($skip_done_files && (-f $o_file)) {
            prt("ICAO: $icao json exists. skipping... $i2 of $max\n") if (VERB1());
            next;
        }
        prt("ICAO: $icao: $alat,$alon - doing json... $i2 of $max\n") if (VERB5());
        # my $b = Bucket2->new();
        my $b = Bucket->new();
        $b->set_bucket($alon,$alat);

        # start JSON text with base
        $line = $base;
        $line .= "\n" if ($add_newline);
        $line .= ',"type":'.$type;  # 1 land, 16 sea, 17 heli
        $line .= ',"icao":"'.$icao.'"';
        $line .= ',"name":"'.$name.'"';
        $line .= ',"lat":'.$alat;
        $line .= ',"lon":'.$alon;
        $line .= ',"rwys":'.$rwycnt;
        $line .= ',"ils":'.$ils;
        $line .= ',"elev":'.$elev;
        # TODO - CHECK bucket code - but looks ok
        $line .= ',"index":'.$b->gen_index();
        $line .= ',"path":"'.$b->gen_base_path().'"';
        $line .= "\n" if ($add_newline);
        $rcnt = scalar @{$rwa};
        # 20131111 - always add, even if an empty array
        $line .= ',"runways":[';
        if ($rcnt) {
            $line .= "\n" if ($add_newline);
            prt("RWYS: $icao adding $rcnt...\n") if (VERB5());
            for ($j = 0; $j < $rcnt; $j++) {
                $j2 = $j + 1;
                #
                # 0     1       2   3 4    5 6 7 8    9           10              11       12   13 14 15 16 17   18          19             20        21   22 23 24 25
                # 100   60.96   1   1 0.25 0 2 1 07   49.01911500 -122.37996700    0.00    0.00 3  5  0  0  25   49.02104800 -122.34005800  131.06    0.00 3  11 0  1
                # 100   60.96   1   1 0.25 0 2 1 01   49.01877000 -122.37871800   75.90    0.00 3  0  0  1  19   49.03176400 -122.36917600    0.00    0.00 3  10 0  0
                # 100   28.96   3   0 0.00 0 0 0 01L  49.02608640 -122.37408779    0.00    0.00 1  0  0  0  19R  49.02976278 -122.37147182    0.00    0.00 1   0 0  0
                $rrwy = ${$rwa}[$j];
                $racnt = scalar @{$rrwy};
                if ($racnt < 20) {
                    prtw("WARNING: icao=$icao: Array count $racnt! SKIPPING\n");
                    prt(join(",",@{$rrwy})."\n");
                    next;
                }
                # hmmmm, seems this is NOT always with BOTH ends!!! - see BIKF, BKPR, ....
                # AHA, seems when there are HELIPORTS also
                $type = ${$rrwy}[1]; #0  - 100 for land runways
                $wid  = ${$rrwy}[1]; #1  - 29.87 - Width of runway in metres Two decimal places recommended. Must be >= 1.00
                $surf = ${$rrwy}[2]; #2  - 3 - Code defining the surface type (concrete, asphalt, etc) Integer value for a Surface Type Code
                $code = ${$rrwy}[3]; #3  - 0 - Code defining a runway shoulder surface type 0=no shoulder, 1=asphalt shoulder, 2=concrete shoulder
                $smth = ${$rrwy}[4]; #4  - 0.15 - Runway smoothness (not used by X-Plane yet) 0.00 (smooth) to 1.00 (very rough). Default is 0.25
                $ctln = ${$rrwy}[5]; #5  - 0 - Runway centre-line lights 0=no centerline lights, 1=centre line lights
                $elit = ${$rrwy}[6]; #6  - 0 - Runway edge lighting (also implies threshold lights) 0=no edge lights, 2=medium intensity edge lights
                # #7  - 1 - Auto-generate distance-remaining signs (turn off if created manually) 0=no auto signs, 1=auto-generate signs
                # #The following fields are repeated for each end of the runway
                $rwy1 = ${$rrwy}[8]; #8  - 13L - Runway number (eg. 31R, 02). Leading zeros are required. Two to three characters. Valid suffixes: L, R or C (or blank)
                $lat1 = sprintf("%.8f",${$rrwy}[9]); #9  - 47.53801700 - Latitude of runway threshold (on runway centerline) in decimal degrees Eight decimal places supported
                $lon1 = sprintf("%.8f",${$rrwy}[10]); #10 - -122.30746100 - Longitude of runway threshold (on runway centerline) in decimal degrees Eight decimal places supported
                # #11 - 73.15 - Length of displaced threshold in metres (this is included in implied runway length) Two decimal places (metres). Default is 0.00
                # #12 - 0.00 - Length of overrun/blast-pad in metres (not included in implied runway length) Two decimal places (metres). Default is 0.00
                # #13 - 2 - Code for runway markings (Visual, non-precision, precision) Integer value for Runway Marking Code
                # #14 - 0 - Code for approach lighting for this runway end Integer value for Approach Lighting Code
                # #15 - 0 - Flag for runway touchdown zone (TDZ) lighting 0=no TDZ lighting, 1=TDZ lighting
                # #16 - 1 - Code for Runway End Identifier Lights (REIL) 0=no REIL, 1=omni-directional REIL, 2=unidirectional REIL
                $rwy2 = ${$rrwy}[17]; #17 - 31R
                $lat2 = sprintf("%.8f",${$rrwy}[18]); #18 - 47.52919200
                $lon2 = sprintf("%.8f",${$rrwy}[19]); #19 - -122.30000000
                # #20 - 110.95 
                # #21 - 0.00 
                # #22 - 2
                # #23 - 0
                # #24 - 0
                # #25 - 1
                $rlen = fg_geo_inverse_wgs_84($lat1, $lon1, $lat2, $lon2, \$az1, \$az2, \$dist);
                $line .= '{';
                $line .= '"len_m":'.int($dist);
                $line .= ',"wid_m":'.$wid;
                $line .= ',"hdg":'.int($az1);
                $line .= ',"surf":"';
                if (defined $runway_surface{$surf}) {
                    $line .= $runway_surface{$surf};
                } else {
                    $line .= $surf;
                }
                $line .= '"';
                $line .= ',"rwy1":"'.$rwy1.'"';
                $line .= ',"lat1":'.$lat1;
                $line .= ',"lon1":'.$lon1;
                $line .= ',"rwy2":"'.$rwy2.'"';
                $line .= ',"lat2":'.$lat2;
                $line .= ',"lon2":'.$lon2;
                $line .= "}";
                if ($j2 < $rcnt) {
                    $rrwy = ${$rwa}[$j2];
                    $racnt = scalar @{$rrwy};
                    $line .= "," if ($racnt >= 20);
                }
                $line .= "\n" if ($add_newline);
            }
        }
        $line .= "]";
        $line .= "\n" if ($add_newline);

        # add helipads, if any
        $rcnt = scalar @{$rha};
        $line .= ',"helipads":[';
        $line .= "\n" if ($add_newline);
        if ($rcnt) {
            prt("HELIPADS: $icao adding $rcnt...\n") if (VERB5());
            # 102 H19  63.98375180 -022.58960171 268.42   35.05   35.05   1 0   0 0.00 0
            # 102 H20  63.97607407 -022.64376126   0.00   49.99   49.99   2 0   0 0.00 0
            for ($j = 0; $j < $rcnt; $j++) {
                $j2 = $j + 1;
                $rrwy = ${$rha}[$j];
                $racnt = scalar @{$rrwy};
                $type = ${$rrwy}[0];  #0 102           Row code for a helipad 101
                $rwy1 = ${$rrwy}[1];  #1 H1            Designator for a helipad. Must be unique at an airport. Usually “H” suffixed by an integer (eg. “H1”, “H3”)
                $lat1 = sprintf("%.8f",${$rrwy}[2]);  #2 47.53918248   Latitude of helipad centre in decimal degrees Eight decimal places supported
                $lon1 = sprintf("%.8f",${$rrwy}[3]);  #3 -122.30722302 Longitude of helipad centre in decimal degrees Eight decimal places supported
                $az1  = ${$rrwy}[3];  #4 2.00          Orientation (true heading) of helipad in degrees Two decimal places recommended
                $wid  = ${$rrwy}[5];  #5 10.06         Helipad length in metres Two decimal places recommended (metres), must be >=1.00
                $dist = ${$rrwy}[6];  #6 10.06         Helipad width in metres Two decimal places recommended (metres), must be >= 1.00
                $surf = ${$rrwy}[7];  #7 1             Helipad surface code Integer value for a Surface Type Code (see below)
                #0             Helipad markings 0 (other values not yet supported)
                #0             Code defining a helipad shoulder surface type 0=no shoulder, 1=asphalt shoulder, 2=concrete shoulder
                #0.25          Helipad smoothness (not used by X-Plane yet) 0.00 (smooth) to 1.00 (very rough). Default is 0.25
                #0             Helipad edge lighting 0=no edge lights, 1=yellow edge lights
                $line .= '{"rwy1":"'.$rwy1.'"';
                $line .= ',"len_m":'.int($dist);
                $line .= ',"wid_m":'.$wid;
                $line .= ',"hdg":'.int($az1);
                $line .= ',"surf":"';
                if (defined $runway_surface{$surf}) {
                    $line .= $runway_surface{$surf};
                } else {
                    $line .= $surf;
                }
                $line .= '"';
                $line .= ',"lat1":'.$lat1;
                $line .= ',"lon1":'.$lon1;
                $line .= "}";
                $line .= "," if ($j2 < $rcnt);
                $line .= "\n" if ($add_newline);
            }
        }
        $line .= "]";
        $line .= "\n" if ($add_newline);

        # add waterways, if any
        $rcnt = scalar @{$rwwa};
        if ($rcnt) {
            # 0   1      2 3  4           5             6  7           8
            # 101 243.84 0 16 29.27763293 -089.35826258 34 29.26458929 -089.35340410
            # 101 22.86  0 07 29.12988952 -089.39561501 25 29.13389936 -089.38060001
            prt("WATERWAYS: $icao adding $rcnt...\n") if (VERB5());
            $line .= ',"waterways":[';
            $line .= "\n" if ($add_newline);
            for ($j = 0; $j < $rcnt; $j++) {
                $j2 = $j + 1;
                $rrwy = ${$rwwa}[$j];
                $racnt = scalar @{$rrwy};
                $type = ${$rrwy}[0]; #0 101 Row code for a water runway 101
                $wid  = ${$rrwy}[1]; #1 49 Width of runway in metres Two decimal places recommended. Must be >= 1.00
                $surf = ${$rrwy}[2]; #2 1 Flag for perimeter buoys 0=no buoys, 1=render buoys
                # The following fields are repeated for each end of the water runway
                $rwy1 = ${$rrwy}[3]; #3 08 Runway number. Not rendered in X-Plane (on water!) Valid suffixes are L, R or C (or blank)
                $lat1 = sprintf("%.8f",${$rrwy}[4]); #4 35.04420911 Latitude of runway end (on runway centerline) in decimal degrees Eight decimal places supported
                $lon1 = sprintf("%.8f",${$rrwy}[5]); #5 -106.59855711 Longitude of runway end (on runway centerline) in decimal degrees Eight decimal places supported            
                $rwy2 = ${$rrwy}[6]; #6 08 Runway number. Not rendered in X-Plane (on water!) Valid suffixes are L, R or C (or blank)
                $lat2 = sprintf("%.8f",${$rrwy}[7]); #7 35.04420911 Latitude of runway end (on runway centerline) in decimal degrees Eight decimal places supported
                $lon2 = sprintf("%.8f",${$rrwy}[8]); #5 -106.59855711 Longitude of runway end (on runway centerline) in decimal degrees Eight decimal places supported            
                $rlen = fg_geo_inverse_wgs_84($lat1, $lon1, $lat2, $lon2, \$az1, \$az2, \$dist);

                # add json
                $line .= '{';
                $line .= '"len_m":'.int($dist);
                $line .= ',"wid_m":'.int($wid);
                $line .= ',"hdg_t":'.int($az1);
                $line .= ',"buoys":';
                $line .= ($surf ? 'true' : 'false');
                $line .= ',"rwy1":"'.$rwy1.'"';
                $line .= ',"lat1":'.$lat1;
                $line .= ',"lon1":'.$lon1;
                $line .= ',"rwy2":"'.$rwy2.'"';
                $line .= ',"lat2":'.$lat2;
                $line .= ',"lon2":'.$lon2;
                $line .= "}";
                $line .= ',' if ($j2 < $rcnt);
                $line .= "\n" if ($add_newline);
            }
            $line .= "]";
            $line .= "\n" if ($add_newline);
        }

        # add frequencies
        $rcnt = scalar @{$rfqa};
        $line .= ',"radios":[';
        $line .= "\n" if ($add_newline);
        if ($rcnt) {
            prt("RADIOS: $icao adding $rcnt...\n") if (VERB5());
            for ($j = 0; $j < $rcnt; $j++) {
                $j2 = $j + 1;
                $rrwy = ${$rfqa}[$j];
                $racnt = scalar @{$rrwy};
                if ($racnt < 2) {
                    prtw("WARNING: freq array ref cnt < 2! got $racnt. \n".join(",",@{$rrwy})."\n");
                    next;
                }
                #0 51 Row code for an ATC COM frequency 50 thru 56 (see above)
                #1 12775 Frequency in MHz x 100 (eg. use 12322 for 123.225MHz) Five digit integer, rounded DOWN where necessary
                #3 ATIS Descriptive name (displayed on X-Plane charts) Short text string (recommend less than 10 characters)
                $type = ${$rrwy}[0];
                $freq = (${$rrwy}[1] / 100);
                $rwy1 = join(' ', splice(@{$rrwy},2));
                $serv = $type;
                if (defined $frequency_code{$type}) {
                    $serv = $frequency_code{$type};
                }
                $line .= "{";
                $line .= '"type":"'.$serv.'"';
                $line .= ',"freq":'.$freq;
                if (length($rwy1)) {
                    $line .= ',"desc":"'.$rwy1.'"';
                }
                $line .= "}";
                if ($j2 < $rcnt) {
                    $rrwy = ${$rfqa}[$j2];
                    $racnt = scalar @{$rrwy};
                    $line .= "," if ($racnt >= 3);
                }
                $line .= "\n" if ($add_newline);
            }
        }
        $line .= "]";
        $line .= "\n" if ($add_newline);

        ###################################################
        # add ILS
        ###################################################
        if ($add_ils_array) {
            my $rilss = get_ils_info($icao);
            $rcnt = scalar @{$rilss};
            $line .= ',"ils":[';
            $line .= "\n" if ($add_newline);
            if ($rcnt) {
                prt("ILS: $icao adding $rcnt...\n") if (VERB5());
                for ($j = 0; $j < $rcnt; $j++) {
                    $j2 = $j + 1;
                    $rrwy = ${$rilss}[$j];
                    $racnt = scalar @{$rrwy};
                    #                0     1     2     3     4     5    6     7   8     9    10
                    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
                    $type = ${$rrwy}[0];
                    $lat1 = sprintf("%.8f",${$rrwy}[1]);
                    $lon1 = sprintf("%.8f",${$rrwy}[2]);
                    $feet = ${$rrwy}[3];
                    $freq  = (${$rrwy}[4] / 100);
                    $rng = ${$rrwy}[5];
                    ###$az1  = int(${$rrwy}[6]);
                    $tmp  = ${$rrwy}[6];
                    if ($type == 6) {
                        $az1 = 0;
                        ###$freq = (substr($tmp,3) / 100);
                        $slope = (substr($tmp,0,3) / 100);
                    } else {
                        $az1 = sprintf("%.2f",$tmp);
                        $slope = 0;
                    }
                    $rwy1 = ${$rrwy}[7];    # actually ID
                    # $icao = ${$rrwy}[8];  # was fetched using this
                    $rwy2 = ${$rrwy}[9];    # associated runway, if ANY
                    $name = ${$rrwy}[10];
                    $serv = $type;
                    if (defined $navaid_code{$type}) {
                        $serv = $navaid_code{$type};
                    }

                    # build json
                    $line .= "{";
                    $line .= '"type":"'.$serv.'"';
                    $line .= ',"freq":'.$freq;
                    $line .= ',"lat":'.$lat1;
                    $line .= ',"lon":'.$lon1;
                    $line .= ',"rng_nm":'.$rng;
                    $line .= ',"alt_fmsl":'.$feet;
                    $line .= ',"hdg":'.$az1 if ($type == 4);
                    $line .= ',"id":"'.$rwy1.'"' if (length($rwy1));
                    $line .= ',"rwy":"'.$rwy2.'"' if (length($rwy2));
                    $line .= ',"desc":"'.$name.'"' if (length($name));
                    $line .= ',"gs":'.$slope if ($type == 6);
                    $line .= "}";
                    $line .= "," if ($j2 < $rcnt);
                    $line .= "\n" if ($add_newline);
                }
            }
            $line .= "]";
            $line .= "\n" if ($add_newline);
        }
        #####################################################

        # add navaids nearyby
        #####################################################
        if ($add_navaids_array) {
            my $rnavs = get_nav_info($alat,$alon,$icao);
            $rcnt = scalar @{$rnavs};
            $line .= ',"navaids":[';
            $line .= "\n" if ($add_newline);
            if ($rcnt) {
                prt("NAV: $icao adding $rcnt...\n") if (VERB5());
                for ($j = 0; $j < $rcnt; $j++) {
                    $j2 = $j + 1;
                    $rrwy = ${$rnavs}[$j];
                    $racnt = scalar @{$rrwy};
                    #                0     1     2     3     4     5    6     7   8     9    10
                    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
                    $type = ${$rrwy}[0];
                    $lat1 = sprintf("%.8f",${$rrwy}[1]);
                    $lon1 = sprintf("%.8f",${$rrwy}[2]);
                    $feet = ${$rrwy}[3];
                    if ($type == 2) {
                        $freq  = ${$rrwy}[4];
                    } else {
                        $freq  = (${$rrwy}[4] / 100);
                    }
                    $rng = ${$rrwy}[5];
                    ###$az1  = int(${$rrwy}[6]);
                    $tmp  = ${$rrwy}[6];
                    if ($type == 6) {
                    #    $az1 = 0;
                    #    ###$freq = (substr($tmp,3) / 100);
                        $slope = (substr($tmp,0,3) / 100);
                    } else {
                    #    $az1 = sprintf("%.2f",$tmp);
                        $slope = 0;
                    }
                    $rwy1 = ${$rrwy}[7];    # actually ID
                    # $icao = ${$rrwy}[8];  # was fetched using this
                    $rwy2 = ${$rrwy}[9];    # associated runway, if ANY
                    $name = ${$rrwy}[10];
                    $dist = ${$rrwy}[11];
                    $az1  = ${$rrwy}[12];
                    $serv = $type;
                    if (defined $navaid_code{$type}) {
                        $serv = $navaid_code{$type};
                    }

                    # build json
                    $line .= "{";
                    $line .= '"type":"'.$serv.'"';
                    $line .= ',"hdg_t":'.$az1;
                    $line .= ',"dist_nm":'.$dist;
                    $line .= ',"freq":'.$freq;
                    $line .= ',"lat":'.$lat1;
                    $line .= ',"lon":'.$lon1;
                    $line .= ',"rng_nm":'.$rng;
                    $line .= ',"alt_fmsl":'.$feet;
                    ###$line .= ',"hdg":'.$az1 if ($type == 4);
                    $line .= ',"id":"'.$rwy1.'"' if (length($rwy1));
                    $line .= ',"rwy":"'.$rwy2.'"' if (length($rwy2));
                    $line .= ',"desc":"'.$name.'"' if (length($name));
                    $line .= ',"gs":'.$slope if ($type == 6);
                    $line .= "}";
                    $line .= "," if ($j2 < $rcnt);
                    $line .= "\n" if ($add_newline);
                }
            }
            $line .= "]";
            $line .= "\n" if ($add_newline);
        }
        $line .= "}\n";
        rename_2_old_bak($o_file);
        write2file($line,$o_file);
        $json_count++;
        $json_bytes += length($line);
        prt("ICAO: $icao json written to [$o_file]. $i2 of $max\n") if (VERB1());
        if ($i && (($i % 250) == 0)) {
            $elap = tv_interval ( $bgntm, [gettimeofday]);
            $lnspsec = ($i2 / $elap);
            $remain =  (($max / $lnspsec) - $elap);
            $lnspsec = (int($lnspsec * 10) / 10);
            prt("File $i2 of $max (est $lnspsec files/sec, elap=".secs_HHMMSS(int($elap)).", rem=".secs_HHMMSS(int($remain)).").\n");
        }
    }   # for ($i = 0; $i < $max; $i++)

    ##### all done #####
    $elap = tv_interval ( $bgntm, [gettimeofday]);
    $lnspsec = ($i / $elap);
    $remain =  (($max / $lnspsec) - $elap);
    $lnspsec = (int($lnspsec * 10) / 10);
    prt("File $i of $max (est $lnspsec files/sec, elap=".secs_HHMMSS(int($elap)).", rem=".secs_HHMMSS(int($remain)).").\n");
}

################################################################
# 1000 Version - data cycle 2012.08, build 20121293
sub load_apt_data {
    prt("Loading $aptdat file ...\n");
    mydie("ERROR: Can NOT locate $aptdat ...$!...\n") if ( !( -f $aptdat) );
    ###open IF, "<$aptdat" or mydie("OOPS, failed to open [$aptdat] ... check name and location ...\n");
    open IF, "<$aptdat" or mydie( "ERROR: CAN NOT OPEN $aptdat...$!...\n" );
    ##prt( "Processing $cnt lines ... airports, runways, and taxiways ...\n" );
    ##set_apt_version( \@lines, $cnt );
    my ($rlat1,$rlat2,$rlon1,$rlon2,$type,$len,$lasttype,@arr,@arr2,$ils,$elev_ft_AMSL);
    my ($apline,$ra,$helicnt,$wwcnt,$trcnt);
    my (@sorted, $o_file,$rwwa);
    my ($i,$rwa,$msg);
    my ($tlat,$tlon);   # tower/viewport location
    my @runways = ();
    my @heliways = ();
    my @closedapts = ();
    my @helipads = ();
    my @seaapts = ();
    my @majapts = ();
    my @freqs = ();
    my @waterways = ();
    $lasttype = 0;
    my $estmax = 2465650;   # was 2133071;
    my $bgntm = [gettimeofday];
    my ($elap,$lnspsec,$remain);
    $helicnt = 0;
    $rwycnt = 0;
    $wwcnt = 0;
    $ra = \@aptlist;
    $tlat = 999;
    $tlon = 999;
    my $aptcount = 0;
    while ($line = <IF>) {
        chomp $line;
        $line = trimall($line);
        $len = length($line);
        if (($. % 50000) == 0) {
            $elap = tv_interval ( $bgntm, [gettimeofday]);
            $lnspsec = $. / $elap;
            $remain = ($estmax / $lnspsec) - $elap;
            prt("Line $. of $estmax (est ".int($lnspsec)." lns/sec, elap=".secs_HHMMSS(int($elap)).", rem=".secs_HHMMSS(int($remain)).").\n");
        }
        next if ($len == 0);
        if ($. < 3) {
            if ($. == 2) {
                $o_file = $out_path.$PATH_SEP."VERSION.apt.txt";
                rename_2_old_bak($o_file);
                write2file($line,$o_file);
                push(@files_written,["VERSION.apt.txt",1,51]);
                prt(substr($line,0,50)."..., written to [$o_file]\n");
            }
            next;
        }
        ###prt("$.: $line\n");
        @arr = split(/\s+/,$line);
        $type = $arr[0];
        if ($type == 99) {
            prt( "$.: Reached END OF FILE ... \n" ); # if ($dbg1);
            last;
        }
        ###pgm_exit(1,"END") if ($. > 15);
        ### if (($line =~ /^$aln\s+/)||($line =~ /^$sealn\s+/)||($line =~ /^$heliln\s+/)) {
        #if ($line =~ /^$aln\s+/) {	# start with '1'
        if (($type == 1)||($type == 16)||($type == 17)) {
            # start of a NEW airport line
            if (length($apt)) {
                # ==========================================================
                # deal with previous
                $trcnt = $rwycnt;
                $trcnt += $helicnt;
                $trcnt += $wwcnt;
                $msg = '';
                # 20131118 - if tower/viewport location valid, use that
                if (in_world_range($tlat,$tlon)) {
                    $alat = $tlat;
                    $alon = $tlon;
                    $msg = 'twr ';
                } else {
                if ($trcnt > 0) {
                    $alat = $glat / $trcnt;
                    $alon = $glon / $trcnt;
                    if (!in_world_range($alat,$alon)) {
                        prtw("WARNING: $apline: OOW [$apt] $alat,$alon $rwycnt\n");
                        next;
                    }
                } else {
                    $alat = 0;
                    $alon = 0;
                    prtw("WARNING: $.: No RUNWAYS [$apt]\n");
                    next;
                }
                    $msg = 'rwy ';
                }
                # x-plane airport line
                # #   0 1  2 3 4    5++
                # EG: 1 70 0 0 YSVS 1770
                # 0  - Row code for an airport, seaplane base or heliport 1, 16 or 17
                # 1  - Elevation of airport in feet above mean sea level (AMSL)
                # 2  - Flag for control tower (used only in the X-Plane ATC system) 0=no ATC tower, 1=has ATC tower
                # 3  - Deprecated. Use default value (“0”) Use 0
                # 4  - Airport ICAO code. If no ICAO code exists, use FAA code (USA only) Maximum four characters. Must be unique.
                # 5+ - Airport name. May contain spaces. Do not use special (accented) characters Text string (up to 40 characters)
                @arr2 = split(/\s+/,$apt);
                $elev_ft_AMSL = $arr2[1];
                $icao = $arr2[4];
                $name = join(' ', splice(@arr2,5));
                prt( "[$name] $icao $alat $alon, elev.ft.AMSL $elev_ft_AMSL rwys=$rwycnt\n" ) if ($dbg11);
                ###if ($aptcount > 20) {
                ###    pgm_exit(1,"TEMP EXIT\n");
                ###}
                ##prt("[$apt] (with $rwycnt runways at [$alat, $alon]) ...\n");
                ##prt("[$icao] [$name] ...\n");
                my @a = @runways;
                my @f = @freqs;
                my @h = @heliways;
                my @w = @waterways;
                $ils = 0;
                if ($name =~ /\[X\]/) {
                    $ra = \@closedapts;
                    $msg .= 'closed';
                } elsif (($name =~ /\[H\]/)||($lasttype == 17)) {
                    $ra = \@helipads;
                    $msg .= 'heliport';
                } else {
                    if ($lasttype == 1) {
                        $ra = \@aptlist;
                        $msg .= 'land airport';
                        $totaptcnt++;	# count another AIRPORT
                    } elsif ($lasttype == 16) {
                        $ra = \@seaapts;
                        $msg .= 'sea airport';
                    } else {
                        prtw("$.: ERROR: Unknown last type $lasttype. [$apt]\n");
                        pgm_exit(1,"");
                    }
                    $ils = find_ils_for_apt($icao);
                    if ($ils > 0) {
                        push(@majapts, [$lasttype, $icao, $name, $alat, $alon, 0, \@w, $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
                    }
                }
                #                 1,16,17    ZZZZ          ws or average    watr           rwys freq cny   heli ELEV
                #                 0          1      2      3      4      5  6     7        8    9    10    11   12
                # push(@aptlist, [$lasttype, $icao, $name, $alat, $alon, 0, \@w,  $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
                push(@{$ra}, [$lasttype, $icao, $name, $alat, $alon, 0, \@w, $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
                $aptcount++;
            } elsif (length($apt)) {
                prtw("WARNING: $.: Skipping line [$line]\n");
                pgm_exit(1,"");
            }
            $apline = $.;
            $apt = $line;   # set the NEW AIRPORT line
            $rwycnt  = 0;   # restart RUNWAY counter
            $helicnt = 0;   # restart helipad counter
            $wwcnt   = 0;   # restart waterway counter
            $glat    = 0;   # clear lat accumulator
            $glon    = 0;   # clear lon accumulator
            $tlat    = 999; # clear Tower/Viewport location
            $tlon    = 999;
            @runways = ();
            @freqs = ();
            @heliways = ();
            @waterways = ();
            $lasttype = $type;  # keep LAST type
            prt("$apt\n") if ($dbg10);
        #} elsif ($line =~ /^$rln\s+/) {
        } elsif ($type == 100) {	# land runways
            # 0     1       2   3 4    5 6 7 8    9           10              11       12   13 14 15 16 17   18          19             20        21   22 23 24 25
            # 100   60.96   1   1 0.25 0 2 1 07   49.01911500 -122.37996700    0.00    0.00 3  5  0  0  25   49.02104800 -122.34005800  131.06    0.00 3  11 0  1
            # 100   60.96   1   1 0.25 0 2 1 01   49.01877000 -122.37871800   75.90    0.00 3  0  0  1  19   49.03176400 -122.36917600    0.00    0.00 3  10 0  0
            # 100   28.96   3   0 0.00 0 0 0 01L  49.02608640 -122.37408779    0.00    0.00 1  0  0  0  19R  49.02976278 -122.37147182    0.00    0.00 1   0 0  0
            $rlat1 = $arr[9];  # [$of_lat1];
            $rlon1 = $arr[10]; # [$of_lon1];
            $rlat2 = $arr[18]; # [$of_lat2];
            $rlon2 = $arr[19]; # [$of_lon2];
            $rlat = sprintf("%.8f",(($rlat1 + $rlat2) / 2));
            $rlon = sprintf("%.8f",(($rlon1 + $rlon2) / 2));
            if (!in_world_range($rlat,$rlon)) {
                prt( "$.: $line [$rlat, $rlon]\n" );
                next;
            }
            $glat += $rlat;
            $glon += $rlon;
            $rwycnt++;  # count another runway
            my @a2 = @arr;
            push(@runways, \@a2);
        } elsif ($type == 101) {	# Water runways
            # 0   1      2 3  4           5             6  7           8
            # 101 243.84 0 16 29.27763293 -089.35826258 34 29.26458929 -089.35340410
            # 101 22.86  0 07 29.12988952 -089.39561501 25 29.13389936 -089.38060001
            # prt("$.: $line\n");
            $rlat1 = $arr[4];
            $rlon1 = $arr[5];
            $rlat2 = $arr[7];
            $rlon2 = $arr[8];
            $rlat = sprintf("%.8f",(($rlat1 + $rlat2) / 2));
            $rlon = sprintf("%.8f",(($rlon1 + $rlon2) / 2));
            if (!in_world_range($rlat,$rlon)) {
                prtw( "WARNING: $.: $line [$rlat, $rlon] NOT IN WORLD\n" );
                next;
            }
            $glat += $rlat;
            $glon += $rlon;
            my @a2 = @arr;
            push(@waterways, \@a2);
            $wwcnt++;
        } elsif ($type == 102) {	# Heliport
            # my $heli =   '102'; # Helipad
            # 0   1  2           3            4      5     6     7 8 9 10   11
            # 102 H2 52.48160046 013.39580674 355.00 18.90 18.90 2 0 0 0.00 0
            # 102 H3 52.48071507 013.39937648 2.64   13.11 13.11 1 0 0 0.00 0
            # prt("$.: $line\n");
            $rlat = sprintf("%.8f",$arr[2]);
            $rlon = sprintf("%.8f",$arr[3]);
            if (!in_world_range($rlat,$rlon)) {
                prtw( "WARNING: $.: $line [$rlat, $rlon] NOT IN WORLD\n" );
                next;
            }
            $glat += $rlat;
            $glon += $rlon;
            my @a2 = @arr;
            push(@heliways, \@a2);
            $helicnt++;
        } elsif ($type == 10) { # old 810 runway/taxiway code!!!
            # 0  1           2             3   4      5   6   7   8  9      10 11 12 13   14
            # 10 68.72074130 -052.79344940 xxx 168.00 160 0.0 0.0 60 161161 1  0  0  0.25 0
            $rlat = $arr[1];
            $rlon = $arr[2];
            $name = $arr[3];
            if ($name ne 'xxx') {
                prtw("WARNING: $.: [$line] NOT A TAXIWAY!\n");
            }
        } elsif ($type == 110) { # 110  Pavement (taxiway or ramp) header Must form a closed loop
        } elsif ($type == 120) { # 120  Linear feature (painted line or light string) header Can form closed loop or simple string
        } elsif ($type == 130) { # 130  Airport boundary header Must form a closed loop
        } elsif ($type == 111) { # 111  Node All nodes can also include a style (line or lights)
        } elsif ($type == 112) { # 112  Node with Bezier control point Bezier control points define smooth curves
        } elsif ($type == 113) { # 113  Node with implicit close of loop Implied join to first node in chain
        } elsif ($type == 114) { # 114  Node with Bezier control point, with implicit close of loop Implied join to first node in chain
        } elsif ($type == 115) { # 115  Node terminating a string (no close loop) No styles used
        } elsif ($type == 116) { # 116  Node with Bezier control point, terminating a string (no close loop) No styles used
        } elsif ($type == 14) { # 14   Airport viewpoint One or none for each airport
            # 14 47.52917900 -122.30434900 100 0 ATC Tower
            $tlat = sprintf("%.8f",$arr[1]);
            $tlon = sprintf("%.8f",$arr[2]);
        } elsif ($type == 15) { # 15   Aeroplane startup location *** Convert these to new row code 1300 ***
        } elsif ($type == 18) { # 18   Airport light beacon One or none for each airport
        } elsif ($type == 19) { # 19   Windsock Zero, one or many for each airport
        } elsif ($type == 20) { # 20   Taxiway sign (inc. runway distance-remaining signs) Zero, one or many for each airport
        } elsif ($type == 21) { # 21   Lighting object (VASI, PAPI, Wig-Wag, etc.) Zero, one or many for each airport
        } elsif ($type == 1000) { # 1000 Airport traffic flow Zero, one or many for an airport. Used if following rules met (rules of same type are ORed together, rules of a different type are ANDed together to). First flow to pass all rules is used.
        } elsif ($type == 1001) { # 1001 Traffic flow wind rule One or many for a flow. Multiple rules of same type ORed
        } elsif ($type == 1002) { # 1002 Traffic flow minimum ceiling rule Zero or one rule for each flow
        } elsif ($type == 1003) { # 1003 Traffic flow minimum visibility rule Zero or one rule for each flow
        } elsif ($type == 1004) { # 1004 Traffic flow time rule One or many for a flow. Multiple rules of same type ORed
        } elsif ($type == 1100) { # 1100 Runway-in-use arrival/departure constraints First constraint met is used. Sequence matters
        } elsif ($type == 1101) { # 1101 VFR traffic pattern Zero or one pattern for each traffic flow
        } elsif ($type == 1200) { # 1200 Header indicating that taxi route network data follows
        } elsif ($type == 1201) { # 1201 Taxi route network node Sequencing is arbitrary. Must be part of one or more edges
        } elsif ($type == 1202) { # 1202 Taxi route network edge Must connect two nodes
        } elsif ($type == 1204) { # 1204 Taxi route edge active zone Can refer to up to 4 runway ends
        } elsif ($type == 1300) { # 1300 Airport location Not explicitly connected to taxi route network
        } elsif (($type >= 50)&&($type <= 56)) { # 50-56 Communication frequencies Zero, one or many for each airport
            my @tfa = @arr;
            push(@freqs, \@tfa); # save the freq array
        } else {
            pgm_exit(1,"$.: [$line] UNPARSED! FIX ME!!\n");
        }
    }

    $elap = tv_interval ( $bgntm, [gettimeofday]);
    $lnspsec = $. / $elap;
    $remain = ($estmax / $lnspsec) - $elap;
    prt("Line $. of $estmax (est ".int($lnspsec)." lns/sec, elap=".secs_HHMMSS(int($elap)).", rem=".secs_HHMMSS(int($remain)).") - all done.\n");
    # prt("Line $. - all done\n");
    close(IF);
    # do any LAST entry
    if (length($apt)) {
        $trcnt = $rwycnt;
        $trcnt += $helicnt;
        $trcnt += $wwcnt;
        if ($trcnt > 0) {
            $alat = $glat / $trcnt;
            $alon = $glon / $trcnt;
            if (!in_world_range($alat,$alon)) {
                prtw("WARNING: $apline: OOW [$apt] $alat,$alon $rwycnt\n");
            }
        } else {
            $alat = 0;
            $alon = 0;
            prtw("WARNING: $.: No RUNWAYS [$apt]\n");
        }
        @arr2 = split(/ /,$apt);
        $elev_ft_AMSL = $arr2[1];
        $icao = $arr2[4];
        $name = join(' ', splice(@arr2,5));
        ###prt("$diff [$apt] (with $rwycnt runways at [$alat, $alon]) ...\n");
        ###prt("$diff [$icao] [$name] ...\n");
        my @a = @runways;
        my @f = @freqs;
        my @h = @heliways;
        my @w = @waterways;
        $ils = find_ils_for_apt($icao);
        if ($name =~ /\[X\]/) {
            $ra = \@closedapts;
                $msg = 'closed';
        } else {
            if ($lasttype == 1) {
                $ra = \@aptlist;
                    $msg = 'land airport';
                $totaptcnt++;	# count another AIRPORT
            } elsif ($lasttype == 16) {
                $ra = \@seaapts;
                    $msg = 'sea airport';
            } elsif ($lasttype == 17) {
                $ra = \@helipads;
                    $msg = 'heliport';
            } else {
                prtw("$.: ERROR: Unknown last type $lasttype. [$apt]\n");
                pgm_exit(1,"");
            }
            $ils = find_ils_for_apt($icao);
            if ($ils > 0) {
                push(@majapts, [$lasttype, $icao, $name, $alat, $alon, 0, \@w, $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
            }
        }
        push(@{$ra}, [$lasttype, $icao, $name, $alat, $alon, 0, \@w, $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
    }

    $diff = scalar @aptlist;
    prt("Loaded $diff airports... \n");
    if (!$write_output) {
        return \@aptlist;
    }
    ######################################################################
    @sorted = sort mycmp_ascend_t1 @aptlist;
    $diff = scalar @sorted;
    $o_file = $out_path.$PATH_SEP.$out_base."-icao.csv";
    prt("Loaded $diff airports... writing to $o_file\n");
    $line = 'icao,"name",lat,lon,runways,ils,elev_ft_AMSL'."\n";
    #                 1,16,17    ZZZZ          ws or average    watr           rwys freq cny   heli ELEV
    #                 0          1      2      3      4      5  6     7        8    9    10    11   12
    # push(@aptlist, [$lasttype, $icao, $name, $alat, $alon, 0, \@w,  $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
    for ($i = 0; $i < $diff; $i++) {
        $ra = $sorted[$i];
        ###$type = ${$ra}[0]; # now all type '1' land airports
        $icao = ${$ra}[1];
        $name = fix_airport_name(${$ra}[2]);
        $alat = ${$ra}[3];
        $alon = ${$ra}[4];
        #$bucket = ${$ra}[5];
        $rwwa = ${$ra}[6];
        $rwycnt = ${$ra}[7];
        $rwa  = ${$ra}[8];
        $ils  = ${$ra}[10];
        $elev_ft_AMSL = ${$ra}[12];
        $line .= "$icao,\"$name\",$alat,$alon,$rwycnt,$ils,$elev_ft_AMSL\n";
    }
    rename_2_old_bak($o_file);
    write2file($line,$o_file);
    push(@files_written,[$out_base."-icao.csv",$diff,length($line)]);
    prt("icao CSV written to [$o_file]\n");

    @sorted = sort mycmp_ascend_t1 @seaapts;
    $o_file = $out_path.$PATH_SEP.$out_base."-sea.csv";
    $diff = scalar @sorted;
    prt("Loaded $diff seaports... writing to $o_file\n");
    $line = 'icao,"name",lat,lon,runways,ils,elev_ft_AMSL'."\n";
    #                 1,16,17    ZZZZ          ws or average    watr           rwys freq cny   heli ELEV
    #                 0          1      2      3      4      5  6     7        8    9    10    11   12
    # push(@aptlist, [$lasttype, $icao, $name, $alat, $alon, 0, \@w,  $rwycnt, \@a, \@f, $ils, \@h, $elev_ft_AMSL]);
    for ($i = 0; $i < $diff; $i++) {
        $ra = $sorted[$i];
        ###$type = ${$ra}[0]; # now all type '1' land airports
        $icao = ${$ra}[1];
        $name = fix_airport_name(${$ra}[2]);
        $alat = ${$ra}[3];
        $alon = ${$ra}[4];
        #$bucket = ${$ra}[5];
        $rwwa = ${$ra}[6];
        $rwycnt = ${$ra}[7];
        $rwa  = ${$ra}[8];
        $ils  = ${$ra}[10];
        $elev_ft_AMSL = ${$ra}[12];
        $line .= "$icao,\"$name\",$alat,$alon,$rwycnt,$ils,$elev_ft_AMSL\n";
    }
    rename_2_old_bak($o_file);
    write2file($line,$o_file);
    push(@files_written,[$out_base."-sea.csv",$diff,length($line)]);
    prt("sea CSV written to [$o_file]\n");

    @sorted = sort mycmp_ascend_t1 @helipads;
    $o_file = $out_path.$PATH_SEP.$out_base."-heli.csv";
    $diff = scalar @sorted;
    prt("Loaded $diff heliports... writing to $o_file\n");
    $line = 'icao,"name",lat,lon,runways,ils,elev_ft_AMSL'."\n";
    for ($i = 0; $i < $diff; $i++) {
        $ra = $sorted[$i];
        ###$type = ${$ra}[0]; # now all type '1' land airports
        $icao = ${$ra}[1];
        $name = fix_airport_name(${$ra}[2]);
        $alat = ${$ra}[3];
        $alon = ${$ra}[4];
        #$bucket = ${$ra}[5];
        $rwwa  = ${$ra}[6];
        $rwycnt = ${$ra}[7];
        $rwa  = ${$ra}[8];
        $ils  = ${$ra}[10];
        $elev_ft_AMSL = ${$ra}[12];
        $line .= "$icao,\"$name\",$alat,$alon,$rwycnt,$ils,$elev_ft_AMSL\n";
    }
    rename_2_old_bak($o_file);
    write2file($line,$o_file);
    push(@files_written,[$out_base."-heli.csv",$diff,length($line)]);
    prt("heli CSV written to [$o_file]\n");

    # ===============================================
    # 20131107 - TODO: A thought, this ils.csv is NOT really sufficient - 
    # It is only by ICAO, so for say LFPO there is only 1 entry
    # LFPO,"Paris Orly",48.7269692925,2.3699923175,3,4
    # but as can be seen there are 4 ILS available, but there are actually FIVE(5)!
    # As my findapx LFPO -s will show, there are 3 runways
    # 06/24 - 11977x147 ft, hdg=61,Asphalt 06 48.71996610,2.31692799 (983,197) 24 48.73544710,2.36068699 (0,197)
    # 08/26 - 10895x147 ft, hdg=74,Concrete 08 48.71939910,2.35860099 (0,1050) 26 48.72742210,2.40207799 (1427,0)
    # 02/20 - 7873x197 ft, hdg=18,Concrete 02 48.71772177,2.37680629 (0,0) 20 48.73820555,2.38707369 (0,0)
    # and these RUNWAYS are supported by FOUR(5) ILS frequencies
    # Type  Latitude     Logitude        Alt.  Freq.  Range  Frequency2    ID  Name
    # GS    48.72781100,  002.40413300,   291, 10815,    18,     74.372,  OLE, LFPO 08 LOC (ap=1 2.51Km on 87.9)
    # LOC   48.73638900,  002.36332500,   291, 10850,    18,     61.794,  ORE, LFPO 06 ILS-cat-III (ap=1 1.16Km on 334.9)
    # LOC   48.73966100,  002.38779200,   291, 11030,    18,     18.282,  OLN, LFPO 02 ILS-cat-I (ap=1 1.93Km on 42.8)
    # LOC   48.71934400,  002.31514200,   291, 11090,    18,    241.794,  OLO, LFPO 24 ILS-cat-II (ap=1 4.12Km on 258.2)
    # LOC   48.71863300,  002.35440300,   291, 11175,    18,    254.372,  OLW, LFPO 26 ILS-cat-III (ap=1 1.47Km on 231.1)
    # SOOO, THIS ILS CSV MUST CONTAIN THIS FULL INFORMATION SO THE FACILITY CAN BE DRAW, like in fgfs 'map'!
    # 06/24 both have ILS, 08/26 both have ILS, and 02 
    # so the header should be, and note the addition of HEADING, all impotatn for drawing
    # icao,lat,lon,alt,hdg,range,freq,id,name
    # BUT, all this information IS added to the ICAO.JSON file
    @sorted = sort mycmp_ascend_t1 @majapts;
    $o_file = $out_path.$PATH_SEP.$out_base."-ils.csv";
    $diff = scalar @sorted;
    prt("Loaded $diff ap/ils... writing to $o_file\n");
    $line = 'icao,"name",lat,lon,runways,ils,elev_ft_AMSL'."\n";
    #                 0          1      2      3      4      5        6    7        8    9    10
    # push(@aptlist, [$lasttype, $icao, $name, $alat, $alon, 0, \@w, $rwycnt, \@a, \@f, $ils]);
    for ($i = 0; $i < $diff; $i++) {
        $ra = $sorted[$i];
        ###$type = ${$ra}[0]; # now all type '1' land airports
        $icao = ${$ra}[1];
        $name = fix_airport_name(${$ra}[2]);
        $alat = ${$ra}[3];
        $alon = ${$ra}[4];
        #$bucket = ${$ra}[5];
        $rwwa = ${$ra}[6];
        $rwycnt = ${$ra}[7];
        $rwa  = ${$ra}[8];
        $ils  = ${$ra}[10];
        $elev_ft_AMSL = ${$ra}[12];
        $line .= "$icao,\"$name\",$alat,$alon,$rwycnt,$ils,$elev_ft_AMSL\n";
    }
    push(@files_written,[$out_base."-ils.csv",$diff,length($line)]);
    rename_2_old_bak($o_file);
    write2file($line,$o_file);
    prt("ILS CSV written to [$o_file]\n");
    # ===============================================
    # 20180226 - add CLOSED airports
    @sorted = sort mycmp_ascend_t1 @closedapts;
    $o_file = $out_path.$PATH_SEP.$out_base."-closed.csv";
    $diff = scalar @sorted;
    prt("Loaded $diff closed aps... writing to $o_file\n");
    $line = 'icao,"name",lat,lon,runways,ils,elev_ft_AMSL'."\n";
    #                 0          1      2      3      4      5        6    7        8    9    10
    # push(@aptlist, [$lasttype, $icao, $name, $alat, $alon, 0, \@w, $rwycnt, \@a, \@f, $ils]);
    for ($i = 0; $i < $diff; $i++) {
        $ra = $sorted[$i];
        ###$type = ${$ra}[0]; # now all type '1' land airports
        $icao = ${$ra}[1];
        $name = fix_airport_name(${$ra}[2]);
        $alat = ${$ra}[3];
        $alon = ${$ra}[4];
        #$bucket = ${$ra}[5];
        $rwwa = ${$ra}[6];
        $rwycnt = ${$ra}[7];
        $rwa  = ${$ra}[8];
        $ils  = ${$ra}[10];
        $elev_ft_AMSL = ${$ra}[12];
        $line .= "$icao,\"$name\",$alat,$alon,$rwycnt,$ils,$elev_ft_AMSL\n";
    }
    push(@files_written,[$out_base."-closed.csv",$diff,length($line)]);
    rename_2_old_bak($o_file);
    write2file($line,$o_file);
    prt("CLOSED CSV written to [$o_file]\n");

    ##############################################
    if ($output_full_list) {
        @sorted = sort mycmp_ascend_t1 @aptlist;
        output_apts_to_json(\@sorted);
        @sorted = sort mycmp_ascend_t1 @helipads;
        output_apts_to_json(\@sorted);
        @sorted = sort mycmp_ascend_t1 @seaapts;
        output_apts_to_json(\@sorted);
        # NOTE: closed airports are written to json files....
        @sorted = sort mycmp_ascend_t1 @closedapts;
        output_apts_to_json(\@sorted);
    }
    ##############################################
}

sub load_nav_file {
	prt("\nLoading $navdat file ...\n");
	mydie("ERROR: Can NOT locate [$navdat]!\n") if ( !( -f $navdat) );
	open NIF, "<$navdat" or mydie( "ERROR: CAN NOT OPEN $navdat...$!...\n" );
	my @nav_lines = <NIF>;
	close NIF;
    my $cnt = scalar @nav_lines;
    prt("Loaded $cnt line...\n");
    return \@nav_lines;
}


##############
### functions

# 12/12/2008 - Additional distance calculations
# from 'signs' perl script
# Melchior FRANZ <mfranz # aon : at>
# $Id: signs,v 1.37 2005/06/01 15:53:00 m Exp $

# sub ll2xyz($$) {
sub ll2xyz {
	my $lon = (shift) * $D2R;
	my $lat = (shift) * $D2R;
	my $cosphi = cos $lat;
	my $di = $cosphi * cos $lon;
	my $dj = $cosphi * sin $lon;
	my $dk = sin $lat;
	return ($di, $dj, $dk);
}


# sub xyz2ll($$$) {
sub xyz2ll {
	my ($di, $dj, $dk) = @_;
	my $aux = $di * $di + $dj * $dj;
	my $lat = atan2($dk, sqrt $aux) * $R2D;
	my $lon = atan2($dj, $di) * $R2D;
	return ($lon, $lat);
}

# sub coord_dist_sq($$$$$$) {
sub coord_dist_sq {
	my ($xa, $ya, $za, $xb, $yb, $zb) = @_;
	my $x = $xb - $xa;
	my $y = $yb - $ya;
	my $z = $zb - $za;
	return $x * $x + $y * $y + $z * $z;
}

sub get_bucket_info {
   my ($lon,$lat) = @_;
   #my $b = Bucket2->new();
   my $b = Bucket->new();
   $b->set_bucket($lon,$lat);
   return $b->bucket_info();
}

sub write_nav_csv() {
    my @sorted = sort mycmp_ascend_n0 @navlist;
    my $o_file = $out_path.$PATH_SEP.$out_base."-nav.csv";
    my $diff = scalar @sorted;
    prt("Loaded $diff navaids... writing to $o_file\n");
    my ($i,$ra,$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name);
    my $line = "type,lat,lon,feet,freq,rng,bear,id,icao,rwy,\"name\"\n";
    #                0     1     2     3     4     5    6     7   8     9    10
    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
    for ($i = 0; $i < $diff; $i++) {
        $ra = $sorted[$i];
        $type = ${$ra}[0];
        $nlat = ${$ra}[1];
        $nlon = ${$ra}[2];
        $feet = ${$ra}[3];
        $freq = ${$ra}[4];
        $rng  = ${$ra}[5];
        $bear = ${$ra}[6];
        $id   = ${$ra}[7];
        $icao = ${$ra}[8];
        $rwy  = ${$ra}[9];
        $name = ${$ra}[10];
        $line .= "$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,\"$name\"\n";
    }
    push(@files_written,[$out_base."-nav.csv",$diff,length($line)]);
    rename_2_old_bak($o_file);
    write2file($line,$o_file);
    prt("nav CSV written to [$o_file]\n");
}

sub look_like_icao($) {
    my $icao = shift;
    my $up = uc($icao);
    my $len = length($icao);
    if (($len == 4) && ($up eq $icao)) {
        return 1;
    }
    return 0;
}

# How can I tell if a string is a number?
# The simplest method is:
#         if ($string == "$string") { 
#          # It is a number
#        } 
# Note the use of the == operator to compare the string to its numeric value. 
# However, this approach is dangerous because the $string might contain arbitrary 
# code such as @{[system "rm -rf /"]} which would be executed as a result of the 
# interpolation process. For safety, use this regular expression:
#   if ($var =~ /(?=.)M{0,3}(C[MD]|D?C{0,3})(X[CL]|L?X{0,3})(I[XV]|V?I{0,3})/) {
#    print "$var contains a number.\b";
#  }


# contains digits,commas and 1 period AND
# does not contain alpha's, more than 1 period
# commas or periods at the beggining and ends of
# each line AND
# is not null
sub IsANumber($) {
    my $var = shift;
    if ( ( $var =~ /(^[0-9]{1,}?$)|(\,*?)|(\.{1})/ ) &&
         !( $var =~ /([a-zA-Z])|(^[\.\,]|[\.\,]$)/ ) &&
         ($var ne '') ) {
         return 1;
    } 
    return 0;
}


sub looks_like_rwy($) {
    my $rwy = shift;
    if (length($rwy) > 0) {
        my $ch = substr($rwy,0,1);
        if (IsANumber($ch)) {  # or perhaps if ($ch == "$ch")
            return 1;
        }
    }
    return 0;
}

my %name_exceptions = (
    'BORYSPIL NDB' => 1,
    'DONETSK NDB' => 1,
    'LOPEZ ISLAND NDB' => 1,
    'PINCK NDB' => 1,
    'OKANAGAN NDB' => 1,
    'UTICA NDB' => 1,
    'DURBAN NDB' => 1,
    'NIZHNEYANSK NDB' => 1  # really should sort out LOCATION - Dist = 6585
    );

sub exception_names($) {
    my $name = shift;
    return 1 if (defined $name_exceptions{$name});
    return 0;
}

sub is_ndb_lom($$) {
    my ($ucnm1,$ucnm2) = @_;
    return 1 if (($ucnm1 =~ /NDB/)&&($ucnm2 =~ /LOM/));
    return 1 if (($ucnm1 =~ /LOM/)&&($ucnm2 =~ /NDB/));
    return 0;
}

# THESE SHOULD BE RE-CHECKED - EXCEPTIONS
sub is_big_exception($$) {
    my ($ucnm1,$ucnm2) = @_;
    return 1 if (($ucnm1 =~ /CHIHUAHUA/)&&($ucnm2 =~ /CHIHUAHUA/)); # dist 1223??? 12:3! VOR-DME
    return 1 if (($ucnm1 =~ /CATEY/)&&($ucnm2 =~ /CATEY/)); # dist 376 but one name starts 'EL ' VOR-DME/VORTAC
    return 1 if (($ucnm1 =~ /DONETSK/)&&($ucnm2 =~ /DONETSK/)); # dist 3971??? 13:3! DME/VOR-DME
    return 1 if (($ucnm1 =~ /GUANTANAMO/)&&($ucnm2 =~ /GUANTANAMO/)); # dist 2150??? 13:3! TACAN/VOR
    return 1 if (($ucnm1 =~ /BOURGET/)&&($ucnm2 =~ /BOURGET/)); # dist 92??? 13:12! DME VOR-DME
    return 1 if (($ucnm1 =~ /MEXICALI/)&&($ucnm2 =~ /MEXICALI/)); # Quite CLOSE 1433??? 12:3!
    return 0;
}


# sub filter_nav_list() if ($do_nav_filter);
# a massive SLOW process, mainly to weed out what look like DUPLICATES
# and other 'exceptions'.
sub filter_nav_list() {
    my @sorted = sort mycmp_ascend_n0 @navlist;
    my $max = scalar @sorted;
    my ($i,$ra,$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name);
    my ($j,$ra2,$type2,$nlat2,$nlon2,$feet2,$freq2,$rng2,$bear2,$id2,$icao2,$rwy2,$name2);
    my ($max2,$fnd,$dist,$az1,$az2,$ret,$msg1,$msg2,$i2,$j2);
    my ($ucnm1,$ucnm2,@arr1,@arr2);
    prt("Filtering $max navaids...\n");
    #$line = "type,lat,lon,feet,freq,rng,bear,id,icao,rwy,\"name\"\n";
    #                0     1     2     3     4     5    6     7   8     9    10
    # push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
    my @navs = ();
    my $bgntm = [gettimeofday];
    for ($i = 0; $i < $max; $i++) {
        $i2 = $i + 1;
        $ra = $sorted[$i];
        $type = ${$ra}[0];
        $nlat = ${$ra}[1];
        $nlon = ${$ra}[2];
        $feet = ${$ra}[3];
        $freq = ${$ra}[4];
        $rng  = ${$ra}[5];
        $bear = ${$ra}[6];
        $id   = ${$ra}[7];
        $icao = ${$ra}[8];
        $rwy  = ${$ra}[9];
        $name = ${$ra}[10];
        $max2 = scalar @navs;
        $fnd = 0;
        if (length($icao) == 0) {
            for ($j = 0; $j < $max2; $j++) {
                $j2 = $j + 1;
                $ra2 = $navs[$j];
                $type2 = ${$ra2}[0];
                $nlat2 = ${$ra2}[1];
                $nlon2 = ${$ra2}[2];
                $feet2 = ${$ra2}[3];
                $freq2 = ${$ra2}[4];
                $rng2  = ${$ra2}[5];
                $bear2 = ${$ra2}[6];
                $id2   = ${$ra2}[7];
                $icao2 = ${$ra2}[8];
                $rwy2  = ${$ra2}[9];
                $name2 = ${$ra2}[10];
                next if (length($icao2) > 0);
                if ( ($id eq $id2) && ($freq == $freq2) ) {
                    $msg1 = join(",", @{$ra})."\n";
                    $msg2 = join(",", @{$ra2})."\n";
                    $ret = fg_geo_inverse_wgs_84($nlat, $nlon, $nlat2, $nlon2, \$az1, \$az2, \$dist);
                    if ($ret > 0) {
                        $dist = $pole_2_pole; # make it BIG
                        $az1 = 0;
                        prtw("$i2:$j2: WARNING: fg_geo_inverse_wgs_84($nlat, $nlon, $nlat2, $nlon2, ...) FAILED!\n");
                    } else {
                        $dist = int($dist);
                        $ucnm1 = uc($name);
                        $ucnm2 = uc($name2);
                        @arr1 = split(/\s+/,$ucnm1);
                        @arr2 = split(/\s+/,$ucnm2);
                        if ($type == $type2) {
                            if ($dist < 10000) {
                                if ($type == 2) {
                                    if (($ucnm1 eq $ucnm2) && (exception_names($ucnm1))) {
                                        $fnd = 1;   # exception - drop duplication
                                        prt("$i2:$j2: NDB exception - Dist $dist! Dropping first\n".$msg1.$msg2) if (VERB9());
                                    } elsif (is_ndb_lom($ucnm1,$ucnm2)) {
                                        $fnd = 1;   # exception for NDB and LOM
                                        prt("$i2:$j2: NDB and LOM - Dist $dist! Dropping first\n".$msg1.$msg2) if (VERB9());
                                    } elsif (($arr1[0] eq $arr2[0]) && ($dist < 1000)) {
                                        $fnd = 1;   # ok name starts same like
                                        # 2,-42.72933333,170.95622222,0,310,100,0.0,HK,,,HOKITIKA NDB-DME
                                        # 2,-42.72933333,170.95622222,0,310,50,0.0,HK,,,HOKITIKA NDB
                                        prt("$i2:$j2: NDB DUPLICATION - Dist $dist! Dropping first\n".$msg1.$msg2) if (VERB9());
                                    } else {
                                        prt("$i2:$j2: Potential NDB DUPLICATION - Dist $dist! CHECK ME!\n".$msg1.$msg2);
                                    }
                                } elsif ($dist < 1000) {
                                    if ($arr1[0] eq $arr2[0]) {
                                        prt("$i2:$j2: NDB DUPE - SAME FIRST NAME - Dist $dist! Dropping first\n".$msg1.$msg2) if (VERB9());
                                        $fnd = 1;
                                    }

                                } else {
                                    prt("$i2:$j2: Potential DUPLICATION - Dist $dist! CHECK ME!\n".$msg1.$msg2);
                                }
                            }
                        } else {
                            if ($dist < 20) {
                                # *** CO-LOCATION ***
                                # ok, decide these can be dropped without notice if
                                if (( ($type == 3) && ($type2 == 13) ) || ( ($type == 13) && ($type2 == 3) )) {
                                    # like AOSTA DME <=> AOSTA VOR-DME Dist 0 or close, SAME frequency
                                    $fnd = 1;
                                    prt("$i2:$j2: Combine VOR & VOR-DME - Dist $dist dropping first!\n".$msg1.$msg2) if (VERB9());
                                } elsif (( ($type == 3) && ($type2 == 12) ) || ( ($type == 12) && ($type2 == 3) )) {
                                    # like AOSTA DME <=> AOSTA VOR-DME Dist 0 or close, SAME frequency
                                    $fnd = 1;
                                    prt("$i2:$j2: Combine VOR & VOR-DME - Dist $dist dropping first!\n".$msg1.$msg2) if (VERB9());
                                } elsif ($ucnm1 eq $ucnm2) {
                                    $fnd = 1;
                                    prt("$i2:$j2: Combine SAME NAME - Dist $dist dropping first!\n".$msg1.$msg2) if (VERB9());
                                } elsif ($arr1[0] eq $arr2[0]) {
                                    $fnd = 1;
                                    prt("$i2:$j2: Combine FIRST NAME - Dist $dist dropping first!\n".$msg1.$msg2) if (VERB9());
                                } else {
                                    prt("$i2:$j2: Combine these - CO-LOCATED - Dist $dist dropping first!\n".$msg1.$msg2);
                                    $fnd = 1;
                                }
                            } elsif ($dist < 10000 ) {
                                if ( ($ucnm1 eq $ucnm2) && ($dist < 1000) ) {
                                    prt("$i2:$j2: Close $dist, and SAME NAME, freq, id $type:$type2! Dropping first\n".$msg1.$msg2) if (VERB9());
                                    $fnd = 1;
                                } elsif ( ($arr1[0] eq $arr2[0]) && ($dist < 1000) ) {
                                    prt("$i2:$j2: Close $dist, and SAME FIRST NAME, freq, id $type:$type2! Dropping first\n".$msg1.$msg2) if (VERB9());
                                    $fnd = 1;
                                } elsif (is_big_exception($ucnm1,$ucnm2)) {
                                    prt("$i2:$j2: Close $dist, special exceptions. CHECK ME! $type:$type2! Dropping first\n".$msg1.$msg2) if (VERB9());
                                    $fnd = 1;
                                } else {
                                    prt("$i2:$j2: WARNING: Quite CLOSE $dist??? $type:$type2!\n".$msg1.$msg2);
                                }
                            }
                        }
                    }
                }
                last if ($fnd); # found dupe - dropping one
            }   # for ($j = 0; $j < $max2; $j++)
        }
        if ($fnd == 0) {
            push(@navs,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
        }
    }
    @navlist = @navs;
    $i = scalar @navlist;
    my $elap = tv_interval ( $bgntm, [gettimeofday]);
    prt("Returning $i of $max. That mess took ".secs_HHMMSS(int($elap))."\n");
}

sub  write_nav_list() {
    if ( -f $navdat2) {
        prt("File $navdat2 already exist...\n");
        return;
    }
    my $max = scalar @navlist;
    prt("Writing $max nav records to $navdat2...\n");
    my ($i,$rnav,$line);
    if (! open(FIL,">$navdat2")) {
        pgm_exit(1,"Unable to create $navdat2!\n");
    }
    for ($i = 0; $i < $max; $i++) {
        $rnav = $navlist[$i];
        $line = join(" ",@{$rnav});
        print FIL "$line\n";
    }
    close FIL;
    prt("Written $max nav records to $navdat2...\n");
}

# ============================================================
# 20131123 - new tests added mainly for 6 GS and 12 VOR-DME
sub looks_like_number($) {
    my $txt = shift;
    $txt = substr($txt,1) if ($txt =~ /^-/); # remove any beginning minus sign
    return 1 if ($txt =~ /^\d+$/);
    return 0;
}
sub looks_like_freq($) {
    my $txt = shift;
    my $len = length($txt);
    return 0 if ($len < 5); # expect at least 5 digits
    return looks_like_number($txt);
}
sub looks_like_id($) {
    my $txt = shift;
    my $len = length($txt);
    return 0 if ($len < 2); # expect at least 2 chars
    my $utx = uc($txt);
    return 0 if ($utx ne $txt);
    return 1;
}
sub looks_like_bearing($) {
    my $txt = shift;
    return 1 if (IsANumber($txt));
    return 0;
}
# 300327.389
sub looks_like_gs($) {
    my $txt = shift;
    my $len = length($txt);
    return 0 if ($len != 10);
    return IsANumber($txt);
}
# ============================================================

##################################################################################
### Load x-plane earth_nav.dat - all added to @navlist
##############################
sub parse_nav_lines($) {
    my $rnava = shift;
    my $max = scalar @{$rnava};
    # add to my @navlist = ();
    my ($i,$line,$lnn,@arr,$acnt,$type,$len,$vnav);
    my ($nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$name,$rwy);
    my (@sorted,$ra,$diff,$o_file,$tmp,$tmp2);
    $lnn = 0;
    prt("Processing $max line of NAV data...\n");
    for ($i = 0; $i < $max; $i++) {
        $line = ${$rnava}[$i];
        chomp $line;
        $line = trimall($line);
        $len = length($line);
        $lnn++;
        next if ($len == 0);
        if ($lnn < 3) {
            if ($lnn == 2) {
                $o_file = $out_path.$PATH_SEP.'VERSION.nav.txt';
                write2file("$line\n",$o_file);
                push(@files_written,['VERSION.nav.txt',1,51]);
                prt(substr($line,0,50)."..., written to [$o_file]\n");
            }
            next;
        }
        @arr = split(/\s+/,$line);
        $acnt = scalar @arr;
        $type = $arr[0];
        if ($type == 99) {
            prt("$lnn: Reached EOF (99)\n");
            last;
        }
        #0  1           2             3    4     5   6          7    8                 9    10
        #CD LAT         LON           ELEV FREQ  RNG BEARING    ID   NAME              RWY  NAME
        #                             FT         NM. GS Ang          ICAO
        #2  47.63252778 -122.38952778 0      362 50  0.0        BF   NOLLA NDB
        #3  47.43538889 -122.30961111 354  11680 130 19.0       SEA  SEATTLE VORTAC
        #4  47.42939200 -122.30805600 338  11030 18  180.343    ISNQ KSEA               16L ILS-cat-I
        #6  47.46081700 -122.30939400 425  11030 10  300180.343 ISNQ KSEA               16L GS
        if ($acnt < 9) {
            prt("Split only yielded $acnt!\n");
            prt("$lnn: [$line]\n");
            pgm_exit(1,"");
        }

        $nlat = $arr[1];
        $nlon = $arr[2];
        $feet = $arr[3];
        $freq = $arr[4];
        $rng  = $arr[5];
        $bear = $arr[6];
        $id   = $arr[7];
        $icao = $arr[8];
        $name = $icao;
        $rwy  = '';
        if ($type == 2) {
            # 2  NDB - (Non-Directional Beacon) Includes NDB component of Locator Outer Markers (LOM)
            # 2  47.63252778 -122.38952778 0      362 50  0.0        BF   NOLLA NDB
            $icao = '';
            $name = join(' ', splice(@arr,8));
        } elsif ($type == 3) {
            # 3  VOR - (including VOR-DME and VORTACs) Includes VORs, VOR-DMEs and VORTACs
            # 3  47.43538889 -122.30961111 354  11680 130 19.0       SEA  SEATTLE VORTAC
            $icao = '';
            $name = join(' ', splice(@arr,8));
        } elsif ($type == 4) {
            # 4  ILS - LOC Localiser component of an ILS (Instrument Landing System)
            # 0  1           2             3    4     5   6          7    8                  9   10
            # 4  47.42939200 -122.30805600 338  11030 18  180.343    ISNQ KSEA               16L ILS-cat-I
            if ($acnt < 11) {
                prtw("WARNING: Split only yielded $acnt!\n".
                    "$lnn: [$line] SKIPPING\n");
                next;
            }
            $rwy = $arr[9];
            $name = $arr[10];
        } elsif ($type == 5) {
            # 5  LOC - Localiser component of a localiser-only approach Includes for LDAs and SDFs
            # 0  1           2              3    4     5   6         7    8                  9   10
            # 5  40.03460600 -079.02328100  2272 10870 18  236.086   ISOZ 2G9                25  LOC
            # 5  67.01850600 -050.68207200   165 10955 18   61.600   ISF  BGSF               10  LOC
            if ($acnt < 11) {
                prtw("WARNING: Split only yielded $acnt!\n".
                    "$lnn: [$line] SKIPPING\n");
                next;
            }
            $rwy = $arr[9];
            $name = $arr[10];
        } elsif ($type == 6) {
            # 6  GS  - Glideslope component of an ILS Frequency shown is paired frequency, not the DME channel
            # 0  1           2             3    4     5   6          7    8     9   10
            # 6  47.46081700 -122.30939400 425  11030 10  300180.343 ISNQ KSEA  16L GS
            # 0 1           2              3         4    5        6    7   8
            # 6 40.75644400 016.94085000   1184 *NF* 10 300321.163 LIBV 32L GS
            # Got 4 WARNINGS...
            #                 0 1           2            3    4  5          6    7   8
            # WARNING:16455: [6 40.75644400 016.94085000 1184 10 300321.163 LIBV 32L GS] SKIPPING split 9
            # WARNING:16827: [6 24.01447200 121.61319400 52   10 320026.187 RCYU 03 GS] SKIPPING split 9
            #                 0 1           2            3    4  5          6    7    8  9
            # WARNING:16758: [6 28.27461100 068.45741900 185  10 300327.389 MCCT OPJA 33 GS] SKIPPING split 10
            # WARNING:16812: [6 22.74861100 121.09566700 143  10 300038.513 MFNN RCFN 04 GS] SKIPPING split 10
            # $feet = $arr[3];
            # $freq = $arr[4];
            # $rng  = $arr[5];
            # $bear = $arr[6];
            # $id   = $arr[7];
            # $icao = $arr[8];
            if ($acnt < 11) {
                if (($acnt == 9) && looks_like_number($feet) && looks_like_number($freq) &&
                    looks_like_gs($rng) && look_like_icao($bear) && looks_like_rwy($id) && ($icao eq 'GS')) {
                    $rwy = $id;     # [7] is runway
                    $tmp = $freq;
                    $freq = '19999';    # set dummy freq
                    $tmp2 = $bear;
                    $bear = $rng;
                    $rng = $tmp;    # [4] is range
                    $tmp = $icao;
                    $icao = $tmp2;
                    $id = $icao;
                    $name = 'GS';
                    #prt("CHECK: $type,$nlat,$nlon,a=$feet,f=$freq,r=$rng,b=$bear,id=$id,icao=$icao,rw=$rwy,nm=$name\n");
                } elsif (($acnt == 10) && looks_like_number($feet) && looks_like_number($freq) &&
                    looks_like_gs($rng) && looks_like_id($bear) && look_like_icao($id) && looks_like_rwy($icao) && ($arr[9] eq 'GS')) {
                    $tmp = $freq;
                    $freq = '19999'; # dummy freq
                    $tmp2 = $rng;
                    $rng = $tmp;
                    $tmp = $bear;
                    $bear = $tmp2;
                    $tmp2 = $id;
                    $id = $tmp;
                    $tmp = $icao;
                    $icao = $tmp2;
                    $rwy = $tmp;
                    $name = 'GS';
                    #prt("CHECK: $type,$nlat,$nlon,a=$feet,f=$freq,r=$rng,b=$bear,id=$id,icao=$icao,rw=$rwy,nm=$name\n");
                } else {
                    prtw("WARNING:$lnn: [$line] SKIPPING split $acnt\n");
                    next;
                }
            } else {
                $rwy = $arr[9];
                $name = $arr[10];
            }
        } elsif ($type == 7) {
            # 7  OM  - Outer markers (OM) for an ILS Includes outer maker component of LOMs
            if ($acnt < 11) {
                prtw("WARNING:$lnn: [$line] SKIPPING split $acnt\n");
                next;
            }
            $rwy = $arr[9];
            $name = $arr[10];
        } elsif ($type == 8) {
            # 8  MM  - Middle markers (MM) for an ILS
            # 8  47.47223300 -122.31102500 433  0     0   180.343    ---- KSEA               16L MM
            if ($acnt < 11) {
                prtw("WARNING:$lnn: [$line] SKIPPING split $acnt\n");
                next;
            }
            $rwy = $arr[9];
            $name = $arr[10];
        } elsif ($type == 9) {
            # 9  IM  - Inner markers (IM) for an ILS
            if ($acnt < 11) {
                prtw("WARNING:$lnn: [$line] SKIPPING split $acnt\n");
                next;
            }
            $rwy = $arr[9];
            $name = $arr[10];
        } elsif ($type == 12) {
            # 12 DME - including the DME component of an ILS, VORTAC or VOR-DME Frequency display suppressed on X-Plane charts
            # 0  1           2             3    4     5   6          7    8                  9   10
            # 12 47.43433300 -122.30630000 369  11030 18  0.000      ISNQ KSEA               16L DME-ILS
            # 12 47.43538889 -122.30961111 354  11680 130 0.0        SEA  SEATTLE VORTAC DME
            # exceptions
            # 0  1           2            3    4     5  6   7   8
            # 12 49.22907200 007.41789200 1177 11480 60 0.0 ZWN ZWEIBRUCKEN VOR-DME
            # $feet = $arr[3];
            # $freq = $arr[4];
            # $rng  = $arr[5];
            # $bear = $arr[6];
            # $id   = $arr[7];
            # $icao = $arr[8];
            if (($acnt > 10) && look_like_icao($icao) && looks_like_rwy($arr[9])) {
                $rwy = $arr[9];
                $name = $arr[10];
            } elsif (looks_like_number($feet) && looks_like_freq($freq) && looks_like_number($rng) && looks_like_bearing($bear) && looks_like_id($id)) {
                $icao = ''; # this is NOT an ICAO
                $name = join(' ', splice(@arr,8));
            } else {
                prtw("WARNING:$lnn: [$line] SKIPPING split $acnt\n");
                next;
            }
        } elsif ($type == 13) {
            # 13 Stand-alone DME, or the DME component of an NDB-DME Frequency will displayed on X-Plane charts
            # 0  1           2             3    4     5      6       7    8
            # 13 57.10393300  009.99280800  57  11670 199    0.0     AAL  AALBORG TACAN
            # 13 68.71941900 -052.79275300 172  10875  25    0.0     AS   AASIAAT DME
            $icao = '';
            $name = join(' ', splice(@arr,8));
        } else {
            prtw("WARNING:$lnn: INVALID [$line]\n");
            next;
        }

        #if (($type == 6) && $show_first_6) {
        #    prt("check: $type,$nlat,$nlon,a=$feet,f=$freq,r=$rng,b=$bear,id=$id,icao=$icao,rw=$rwy,nm=$name\n");
        #    $show_first_6--;
        #}

        ##############################################################################
        #               0     1     2     3     4     5    6     7   8     9   10
        push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
        ##############################################################################
    }
    $type = scalar @navlist;
    prt("Collected $type navaids, before filtering...\n");
    filter_nav_list() if ($do_nav_filter);
    write_nav_list();
    write_nav_csv();
}

sub check_files() {
    if (! -f $aptdat) {
        pgm_exit(1,"ERROR: Input file $aptdat does NOT EXIST!\n");
    }
    if (! -f $navdat) {
        pgm_exit(1,"ERROR: Input file $navdat does NOT EXIST!\n");
    }
    if (! -f $licfil) {
        pgm_exit(1,"ERROR: Input file $licfil does NOT EXIST!\n");
    }
    if (! -d $out_path) {
        pgm_exit(1,"ERROR: Ouput path [$out_path] does NOT EXIST!\nCreate the path, and run again...\n");
    }

    copy($licfil,$out_path);
    prt("Copied the licence text to [$out_path]\n");
    #### pgm_exit(0,"TEMP EXIT");
}

sub output_readme() {
    my $o_file = $out_path.$PATH_SEP."README.txt";
    my $txt = "FLIGHTGEAR AIRPORT GENERATION UTILITY - version $VERS\n";

    $txt .= "\nGenerated by $pgmname, on ".lu_get_YYYYMMDD_hhmmss_UTC(time())." UTC\n";
    $txt .= "generated from $aptdat and $navdat data files.\n";
    my $max = scalar @files_written;
    $txt .= "Files written: $max\n"; # join(" ",@files_written)."\n";
    my ($i,$file,$lines,$bytes,$min,$len,$minl,$minb,$nnl,$nnb,$ra);
    my $tot_lines = 0;
    my $tot_bytes = 0;
    $min = 0;
    $minl = 0;
    $minb = 0;
    for ($i = 0; $i < $max; $i++) {
        $ra = $files_written[$i];
        $file = ${$ra}[0];
        $len = length($file);
        $min = $len if ($len > $min);
        $lines = ${$ra}[1];
        $nnl = get_nn($lines);
        $len = length($nnl);
        $minl = $len if ($len > $minl);
        $bytes = ${$ra}[2];
        $nnb = get_nn($bytes);
        $len = length($nnb);
        $minb = $len if ($len > $minb);
        $tot_lines += $lines;
        $tot_bytes += $bytes;
    }
    $nnl = get_nn($tot_lines);
    $len = length($nnl);
    $minl = $len if ($len > $minl);
    $nnb = get_nn($tot_bytes);
    $len = length($nnb);
    $minb = $len if ($len > $minb);
    for ($i = 0; $i < $max; $i++) {
        $ra = $files_written[$i];
        $file  = ${$ra}[0];
        $lines = ${$ra}[1];
        $bytes = ${$ra}[2];
        $file .= ' ' while(length($file) < $min);
        $nnl = get_nn($lines);
        $nnl = ' '.$nnl while (length($nnl) < $minl);
        $nnb = get_nn($bytes);
        $nnb = ' '.$nnb while (length($nnb) < $minb);
        $txt .= "$file $nnl lines, $nnb bytes\n"
    }
    $nnl = get_nn($tot_lines);
    $nnb = get_nn($tot_bytes);
    my $bks = util_bytes2ks($tot_bytes);
    $txt .= "Approx. total of $nnl lines, $nnb bytes ($bks)\n";

    $nnl = get_nn($json_count);
    $nnb = get_nn($json_bytes);
    $txt .= "\nPlus $nnl ICAO.json files, $nnb bytes, for each airport.\n";
    $txt .= "\nAnd of course this README.txt\n";
    my $elap = tv_interval ( $t0, [gettimeofday]);
    $nnb = get_nn(int($elap));
    $txt .= "\nProcessing took $nnb seconds, or ".secs_HHMMSS(int($elap))."\n";
    $txt .= "\n# eof\n";
    rename_2_old_bak($o_file);
    write2file($txt,$o_file);
    prt("Summary of output written to $o_file\n");
}

# if more than just ONE space, them push an empty item
sub spl_space_split($) {
    my $line = shift;
    my $len = length($line);
    my ($i,$ch,$pc,$tag);
    $ch = '';
    my @arr = ();
    $tag = '';
    for ($i = 0; $i < $len; $i++) {
        $pc = $ch;
        $ch = substr($line,$i,1);
        if ($ch =~ /\s/) {
            push(@arr,$tag) if (length($tag));
            $tag = '';
            if ($pc =~ /\s/) {
                push(@arr,"");
            }
        } else {
            $tag .= $ch;
        }
    }
    push(@arr,$tag) if (length($tag));
    return \@arr;
}

sub do_nav_load() {
    if (-f $navdat2) {
        if (open FIL,"<$navdat2") {
            my @lines = <FIL>;
            close FIL;
            my $max = scalar @lines;
            prt("Loaded $max lines from $navdat2\n");
            my ($i,$line,$ra,$len);
            my ($type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name);
            for ($i = 0; $i < $max; $i++) {
                $line = $lines[$i];
                chomp $line;
                $ra = spl_space_split($line);
                $len = scalar @{$ra};
                if ($len < 11) {
                    pgm_exit(1,"Bad line [$line] len $len!\n");
                }
                $type = ${$ra}[0];
                $nlat = ${$ra}[1];
                $nlon = ${$ra}[2];
                $feet = ${$ra}[3];
                $freq = ${$ra}[4];
                $rng  = ${$ra}[5];
                $bear = ${$ra}[6];
                $id   = ${$ra}[7];
                $icao = ${$ra}[8];
                $rwy  = ${$ra}[9];
                $name = join(' ', splice(@{$ra},10));
                ##############################################################################
                #               0     1     2     3     4     5    6     7   8     9   10
                #               4    39.9  5.877 660   108   18   281.6 IMQS 40N   29  ILS-cat-I
                push(@navlist,[$type,$nlat,$nlon,$feet,$freq,$rng,$bear,$id,$icao,$rwy,$name]);
                ##############################################################################
            }
            $type = scalar @navlist;
            prt("Collected $type navaids, from $navdat2\n");
            write_nav_csv();
            $line = get_nav_vers();
            my $o_file = $out_path.$PATH_SEP.'VERSION.nav.txt';
            rename_2_old_bak($o_file);
            write2file("$line\n",$o_file);
            push(@files_written,['VERSION.nav.txt',1,51]);
            prt(substr($line,0,50)."..., written to [$o_file]\n");
            return;
        }

    }
    my $nav_ref = load_nav_file();
    parse_nav_lines($nav_ref);
    
}


############################################
### MAIN ###
parse_args(@ARGV);	# collect command line arguments ...
# prt("Not exists $notexist\n");
check_files();

do_nav_load();

###pgm_exit(0,"");

load_apt_data();  # load apt.dat, and output found to json

output_readme();
my $elapsed = tv_interval ( $t0, [gettimeofday]);
prt( "Ran for $elapsed seconds ... ".secs_HHMMSS(int($elapsed))."\n" );
pgm_exit(0,"");
############################################################

sub need_arg {
    my ($arg,@av) = @_;
    pgm_exit(1,"ERROR: [$arg] must have a following argument!\n") if (!@av);
}

sub parse_args {
    my (@av) = @_;
    my ($arg,$sarg);
    while (@av) {
        $arg = $av[0];
        if ($arg =~ /^-/) {
            $sarg = substr($arg,1);
            $sarg = substr($sarg,1) while ($sarg =~ /^-/);
            if (($sarg =~ /^h/i)||($sarg eq '?')) {
                give_help();
                pgm_exit(0,"Help exit(0)");
            } elsif ($sarg =~ /^v/) {
                if ($sarg =~ /^v.*(\d+)$/) {
                    $verbosity = $1;
                } else {
                    while ($sarg =~ /^v/) {
                        $verbosity++;
                        $sarg = substr($sarg,1);
                    }
                }
                prt("Verbosity = $verbosity\n") if (VERB1());
            } elsif ($sarg =~ /^l/) {
                if ($sarg =~ /^ll/) {
                    $load_log = 2;
                } else {
                    $load_log = 1;
                }
                prt("Set to load log at end. ($load_log)\n") if (VERB1());
            } elsif ($sarg =~ /^o/) {
                need_arg(@av);
                shift @av;
                $sarg = $av[0];
                $out_path = $sarg;
                prt("Set out path to [$out_path].\n") if (VERB1());
            } elsif ($sarg =~ /^i/) {
                $add_ils_array = 1;
                prt("Set to add ils array to ICAO airport json.\n") if (VERB1());
            } elsif ($sarg =~ /^n/) {
                $add_navaids_array = 1;
                prt("Set to add navaids array to ICAO airport json.\n") if (VERB1());
            } else {
                pgm_exit(1,"ERROR: Invalid argument [$arg]! Try -?\n");
            }
        } else {
            $out_path = $arg;
            prt("Set output path to [$out_path]\n") if (VERB1());
        }
        shift @av;
    }

    if ($debug_on) {
        prtw("WARNING: DEBUG is ON!\n");
        if (length($out_path) ==  0) {
            $out_path = $dout_path;
            prt("Set DEFAULT output path to [$out_path]\n");
        }
        $add_ils_array = 1;
    }
    if (length($out_path) ==  0) {
        pgm_exit(1,"ERROR: No output path found in command!\n");
    }
    if (! -d $out_path) {
        pgm_exit(1,"ERROR: Ouput path [$out_path] does NOT exist! Check name, location...\n");
    }
}

sub give_help {
    prt("$pgmname: version $VERS\n");
    prt("Usage: $pgmname [options] out_directory\n");
    prt("Options:\n");
    prt(" --help  (-h or -?) = This help, and exit 0.\n");
    prt(" --verb[n]     (-v) = Bump [or set] verbosity. (def=$verbosity)\n");
    prt(" --load        (-l) = Load LOG at end. (def=$outfile)\n");
    prt(" --out <dir>   (-o) = Write output to directory. Must exist. (def=$out_path).\n");
    prt(" --nav         (-n) = Add navaids array to ICAO airport json. (def=$add_navaids_array)\n");
    prt(" --ils         (-i) = Add ils array to ICAO airport json. (def=$add_ils_array)\n");
    prt("\n");

}

# eof - xp2csv.pl

# X-Plane apt.dat codes
my $x_code = <<EOF;

FROM : http://data.x-plane.com/designers.html#Formats

Airports:  1000 Version (latest - revised Mar 2012), 850 Version (expired) 715 Version (expired)
================================================================================================
from : http://data.x-plane.com/file_specs/XP%20APT1000%20Spec.pdf
1    Land airport header
16   Seaplane base header
17   Heliport header
100  Runway
101  Water runway
102  Helipad
110  Pavement (taxiway or ramp) header Must form a closed loop
120  Linear feature (painted line or light string) header Can form closed loop or simple string
130  Airport boundary header Must form a closed loop
111  Node All nodes can also include a “style” (line or lights)
112  Node with Bezier control point Bezier control points define smooth curves
113  Node with implicit close of loop Implied join to first node in chain
114  Node with Bezier control point, with implicit close of loop Implied join to first node in chain
115  Node terminating a string (no close loop) No “styles” used
116  Node with Bezier control point, terminating a string (no close loop) No “styles” used
14   Airport viewpoint One or none for each airport
15   Aeroplane startup location *** Convert these to new row code 1300 ***
18   Airport light beacon One or none for each airport
19   Windsock Zero, one or many for each airport
20   Taxiway sign (inc. runway distance-remaining signs) Zero, one or many for each airport
21   Lighting object (VASI, PAPI, Wig-Wag, etc.) Zero, one or many for each airport
1000 Airport traffic flow Zero, one or many for an airport. Used if following rules met (rules of same type are ORed together, rules of a different type are ANDed together to). First flow to pass all rules is used.
1001 Traffic flow wind rule One or many for a flow. Multiple rules of same type “ORed”
1002 Traffic flow minimum ceiling rule Zero or one rule for each flow
1003 Traffic flow minimum visibility rule Zero or one rule for each flow
1004 Traffic flow time rule One or many for a flow. Multiple rules of same type “ORed”
1100 Runway-in-use arrival/departure constraints First constraint met is used. Sequence matters
1101 VFR traffic pattern Zero or one pattern for each traffic flow
1200 Header indicating that taxi route network data follows
1201 Taxi route network node Sequencing is arbitrary. Must be part of one or more edges
1202 Taxi route network edge Must connect two nodes
1204 Taxi route edge active zone Can refer to up to 4 runway ends
1300 Airport location Not explicitly connected to taxi route network
50–56 Communication frequencies Zero, one or many for each airport

50 ATC – Recorded AWOS, ASOS or ATIS
51 ATC – Unicom Unicom (US), CTAF (US), Radio (UK)
52 ATC – CLD Clearance Delivery
53 ATC – GND Ground
54 ATC – TWR Tower
55 ATC – APP Approach
56 ATC - DEP Departure

Airport line
#   0 1  2 3 4    5++
EG: 1 70 0 0 YSVS 1770
0  - Row code for an airport, seaplane base or heliport 1, 16 or 17
1  - Elevation of airport in feet above mean sea level (AMSL)
2  - Flag for control tower (used only in the X-Plane ATC system) 0=no ATC tower, 1=has ATC tower
3  - Deprecated. Use default value (“0”) Use 0
4  - Airport ICAO code. If no ICAO code exists, use FAA code (USA only) Maximum four characters. Must be unique.
5+ - Airport name. May contain spaces. Do not use special (accented) characters Text string (up to 40 characters)

Runway line
#   0   1     2 3 4    5 6 7 8   9            10            11    12   13 14 15 16 17  18           19           20     21   22 23 24 25
EG: 100 29.87 3 0 0.00 0 0 0 16  -24.20505300 151.89156100  0.00  0.00 1  0  0  0  34  -24.19732300 151.88585300 0.00   0.00 1  0  0  0
OR: 100 29.87 1 0 0.15 0 2 1 13L 47.53801700  -122.30746100 73.15 0.00 2  0  0  1  31R 47.52919200 -122.30000000 110.95 0.00 2  0  0  1
Land Runway
0  - 100 - Row code for a land runway (the most common) 100
1  - 29.87 - Width of runway in metres Two decimal places recommended. Must be >= 1.00
2  - 3 - Code defining the surface type (concrete, asphalt, etc) Integer value for a Surface Type Code
3  - 0 - Code defining a runway shoulder surface type 0=no shoulder, 1=asphalt shoulder, 2=concrete shoulder
4  - 0.15 - Runway smoothness (not used by X-Plane yet) 0.00 (smooth) to 1.00 (very rough). Default is 0.25
5  - 0 - Runway centre-line lights 0=no centerline lights, 1=centre line lights
6  - 0 - Runway edge lighting (also implies threshold lights) 0=no edge lights, 2=medium intensity edge lights
7  - 1 - Auto-generate distance-remaining signs (turn off if created manually) 0=no auto signs, 1=auto-generate signs
The following fields are repeated for each end of the runway
8  - 13L - Runway number (eg. 31R, 02). Leading zeros are required. Two to three characters. Valid suffixes: L, R or C (or blank)
9  - 47.53801700 - Latitude of runway threshold (on runway centerline) in decimal degrees Eight decimal places supported
10 - -122.30746100 - Longitude of runway threshold (on runway centerline) in decimal degrees Eight decimal places supported
11 - 73.15 - Length of displaced threshold in metres (this is included in implied runway length) Two decimal places (metres). Default is 0.00
12 - 0.00 - Length of overrun/blast-pad in metres (not included in implied runway length) Two decimal places (metres). Default is 0.00
13 - 2 - Code for runway markings (Visual, non-precision, precision) Integer value for Runway Marking Code
14 - 0 - Code for approach lighting for this runway end Integer value for Approach Lighting Code
15 - 0 - Flag for runway touchdown zone (TDZ) lighting 0=no TDZ lighting, 1=TDZ lighting
16 - 1 - Code for Runway End Identifier Lights (REIL) 0=no REIL, 1=omni-directional REIL, 2=unidirectional REIL
17 - 31R
18 - 47.52919200
19 - -122.30000000
20 - 110.95 
21 - 0.00 
22 - 2
23 - 0
24 - 0
25 - 1

Nav-aids: 810 version (latest - revised Oct 2011), 740 Version (expired)
========================================================================
from : http://data.x-plane.com/file_specs/XP%20NAV810%20Spec.pdf
for earth_nav.dat

2  NDB - (Non-Directional Beacon) Includes NDB component of Locator Outer Markers (LOM)
3  VOR - (including VOR-DME and VORTACs) Includes VORs, VOR-DMEs and VORTACs
4  ILS - LOC Localiser component of an ILS (Instrument Landing System)
5  LOC - Localiser component of a localiser-only approach Includes for LDAs and SDFs
6  GS  - Glideslope component of an ILS Frequency shown is paired frequency, not the DME channel
7  OM  - Outer markers (OM) for an ILS Includes outer maker component of LOMs
8  MM  - Middle markers (MM) for an ILS
9  IM  - Inner markers (IM) for an ILS
12 DME - including the DME component of an ILS, VORTAC or VOR-DME Frequency display suppressed on X-Plane’s charts
13 Stand-alone DME, or the DME component of an NDB-DME Frequency will displayed on X-Plane’s charts

Sample data
0  1           2             3    4     5   6          7    8                 9    10
CD LAT         LON           ELEV FREQ  RNG BEARING    ID   NAME              RWY  NAME
                             FT         NM. GS Ang          ICAO
2  47.63252778 -122.38952778 0      362 50  0.0        BF   NOLLA NDB
3  47.43538889 -122.30961111 354  11680 130 19.0       SEA  SEATTLE VORTAC
4  47.42939200 -122.30805600 338  11030 18  180.343    ISNQ KSEA               16L ILS-cat-I
6  47.46081700 -122.30939400 425  11030 10  300180.343 ISNQ KSEA               16L GS
8  47.47223300 -122.31102500 433  0     0   180.343    ---- KSEA               16L MM
12 47.43433300 -122.30630000 369  11030 18  0.000      ISNQ KSEA               16L DME-ILS
12 47.43538889 -122.30961111 354  11680 130 0.0        SEA  SEATTLE VORTAC DME
13 57.10393300  009.99280800  57  11670 199    0.0     AAL  AALBORG TACAN
13 68.71941900 -052.79275300 172  10875  25    0.0     AS   AASIAAT DME

Fixes: 600 Version (latest - revised July 2009)
===============================================
from : http://data.x-plane.com/file_specs/XP%20FIX600%20Spec.pdf
for earth_fix.dat
Sample
37.428522 -097.419194 ACESI

Airways:  640 Version (latest)
==============================
from : http://data.x-plane.com/file_specs/Awy640.htm
sample
ABCDE  32.283733 -106.898669 ABC    33.282503 -107.280542 2 180 450 J13
ABC    33.282503 -107.280542 DEF    35.043797 -106.816314 2 180 450 J13
DEF    35.043797 -106.816314 KLMNO  35.438056 -106.649536 2 180 450 J13-J14-J15 

ABCDE       Name of intersection or nav-aid at the beginning of this segment (the fix ABCDE in this example). 
32.283733   Latitude of the beginning of this segment. 
-106.898669 Longitude of the beginning of this segment. 
ABC         Name of intersection or nav-aid at the end of this segment (the nav-aid ABC in this example). 
33.282503   Latitude of the end of this segment. 
-107.280542 Longitude of the end of this segment. 
2           This is a "High" airway (1 = "low", 2 = "high").  If an airway segment is both High and Low, then it should be listed twice (once in each category).  This determines if the airway is shown on X-Plane's "High Enroute" or "Low Enroute" charts. 
180         Base of airway in hundreds of feet (18,000 feet in this example). 
450         Top of airways in hundreds of feet (45,000 feet in this example). 
J13         Airway segment name.  If multiple airways share this segment, then all names will be included separated by a hyphen (eg. "J13-J14-J15")  

Astronomical:  740 Version (latest)
===================================
from : http://data.x-plane.com/file_specs/Astro740.htm
sample
 6.752569 -16.713143 -1.43 Sirius
19.846301   8.867385  0.77 Altair
 2.529743  89.264138  1.97 Polaris 

6.752569   Right Ascension in decimal hours.  Always a positive number. 
-16.713143 Declination in decimal degrees.  Positive declinations are north of the celestial equator (eg. the pole star, Polaris, is at a declination of 89.264138 degrees). 
-1.43      Visible magnitude of the star.  This is a weird logarithmic scale (low numbers are brightest), and stars to a magnitude of +6.5 are considered visible to the naked eye (though this will vary hugely with your local seeing conditions, light pollution, altitude, etc.).  Sirius (the brightest star in the night sky) has a negative magnitude (-1.43) because it is very, very bright.  
Sirius     Star name (optional - not used by X-Plane).  

Any units of angular measure can be used for right ascension, but it is customarily 
measured in hours ( h ), minutes ( m ), and seconds ( s ), with 24h being equivalent 
to a full circle.

EOF

sub get_nav_vers() {
    my $txt = "810 Version - data cycle 2013.10, build 20131334, metadata NavXP810. Copyright © 2013, Robin A. Peel (robin\@x-plane.com). This data is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program (\"AptNavGNULicence.txt\"); if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.";
    return $txt;
}

# ================================