gnuais_display

A CGI script to plot GnuAIS data on Google Maps

I've been a very satisfied user of Shipplotter for a while, but I've been happy to discover an open source project giving some AIS decoding capabilities to Linux as well, since I'm more and more moving away from Windows.
GnuAIS works fine with audio coming from the "packet" socket of my FT817/FT857, however I've been unable to run the provided GUI. Map is displayed on the screen but nothing else happens.
Since all received data can be optionally logged into a MySQL database, I thought I might as well use that source for an alternative plotting on maps that could in the futurer be integrataed with other sources (es. ACARS).
My home pc was already running a LAMP (Linux, Apache, MySQL, Perl) platform to support my radio experiments, so all I had to do was gluing together some pieces.
Goggle Maps interaction happens via HTML::GoogleMaps which I found on CPAN.
Database interaction happens via the usual DBI.pm library, while and CGI.pm makes the magic in the Apache interaction.
Please find below an almost functional script: to make it work

get your Google Maps API key, keeping in mind that the server you'll run the script on has to share the same domain you registered, otherwise an error message will be returned form Google. I registered the key for tarapippo.net and put an entry in /etc/hosts mapping test.tarapippo.net to localhost as a workaround
fill in all appropriate fields in the "settings" block
save it in the Apache CGI folder on your web server

Additional info:

script is released to the public under GNU/GPL v3 license
no security concerns were addressed as I only run it for personal use on my internal network
I'm no serious programmer: this is meant to just work

Known issues:

the number of markers bearing a letter is limited to the alphabet set allowed by Google (A-Z ?): from my location it's more than enough but could cause malfunctioning in high traffic environments. Letters are assigned on time basis (A last ship received...)

#!/usr/bin/perl
# gnuias_display - a CGI to plot data from GnuAIS
# (c) 2010 Stefano Sinagra IZ0MJE
# released under GNU/GPL v3 license

use CGI qw/:standard -nosticky/;
use DBI;
use DateTime;
use HTML::GoogleMaps;

### change settings in this block
# db settings
$dbname='DBI:mysql:<database name>:<host>';
$dbuser='<db user>';
$dbpass='<db password>';
# Google Maps settings
$map_key="<Google maps API key>";
# home station coordinates
$home_long=<your home longitude>;
$home_lat=<your home latitude>;

# db connection
$dbh = DBI->connect($dbname,$dbuser,$dbpass) or die DBI->errstr;

$sth = $dbh->prepare('(select mmsi, latitude, longitude, name, destination, ais_position.time from ais_position left join ais_vesseldata using (mmsi) order by ais_position.time desc) union (select mmsi, latitude, longitude, "shore station", "n/a", null from ais_basestation);') or die "Couldn't prepare statement: " . $dbh->errstr;

### map embedding
$map = HTML::GoogleMaps->new(
    key => $map_key,
    height =>480,
    width =>940);
$map->controls(large_map_control, map_type_control);
$map->v2_zoom(10);
$map->center( [$home_long,$home_lat] );
$map->add_marker(point => [$home_long,$home_lat],html => "basestation", noformat => 1 );

$sth->execute();
$marker = 65;
while (@data = $sth->fetchrow_array()) {
    $char = chr($marker);
    $marker++;
    if ($data[4] eq "") { $data[4]="unknown"; }
    if ($data[3] eq "shore station") { $popup = "$data[0] $data[3]";
        } else { $popup = "$data[0] $data[3] dest. $data[4]";}
    $map->add_marker(point => [$data[2],$data[1]], html => $popup, noformat => 1, icon => $char ) };

my ($head, $map_div) = $map->onload_render;

###

       print header,
        start_html('AIS'),
        h1('AIS monitoring'),
        '<body onload="html_googlemaps_initialize()">',
        hr;
print;

print $map_div;

print $head;

print hr;

    $sth->execute();

        # Read the matching records and print them out
        print "<table border=1>";
        print "<tr BGCOLOR='#C0C0C0'><th>marker</th><th>mmsi</th><th>lat</th><th>lon</th><th>description</th><th>destination</th></tr>";
        $marker = 65;
        while (@data = $sth->fetchrow_array()) {
            $char = chr($marker);
            $marker++;
            print "<tr><td align=center>", $char , "</td><td>", $data[0],"</td><td>", $data[1], "</td><td>", $data[2], "</td><td>", $data[3], "</td><td>", $data[4], "</td></tr>";}
        print "</table>";
        $sth->finish;
        $dbh->disconnect;

    print "<p><a href=http://www.itu.int/online/mms/mars/ship_search.sh target='_blank'>Search ship data in ITU database</a>";

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Published: 21Nov10 - Home