[aprssig] AIS on APRS maps

[Heikki Hannikainen]

On Sat, 26 Apr 2008, Kai Gunter Brandt wrote:
> joe at dellabarba.com skrev:
>> On my boat I have APRS and AIS.
>> Is there anything to convert the AIS data to APRS data and would anyone 
>> want to see it if there was?
>
> aprs.he.fi is displaying AIS but i think this is a seperate stream on the sql 
> servers.

   Yup, a good bunch of people running ShipPlotter 
(http://www.coaa.co.uk/shipplotter.htm) are feeding data to 
http://aprs.fi/ - see http://aprs.fi/page/ais_sites for a list. But the 
data is not converted to APRS format as such, it is simply fed to the 
database backend. I don't see much point in converting it to APRS format, 
since there's a lot of additional information in there (ship dimensions, 
MMSI/IMO numbers, vessel classes, heading and course separately...) which 
cannot be put into APRS packets without using custom fields.

   It's useful for SAR folks to have them on the same map, though. A lot of 
volunteer search-and-rescue boats have APRS trackers on them here, they're 
cheaper than AIS gear anyway. They've got amateur licences for automatic 
digipeater stations, and they're installed and maintained by hams.

   The APRS tracker used by the boats can also output APRS positions sent 
by other SAR APRS trackers as NMEA sentences on the serial port. AIS 
receivers can do the same, and a mapping application or a radar display 
can then plot all of the data on the same display in the boat.

PS. There's also a Google Earth interface on aprs.fi - install Google 
Earth from earth.google.com and click on the 'Google Earth KML' link on 
aprs.fi to get a live APRS overlay without installing additional software.

   Drop me an email, if you have a spare VHF FM receiver with a 
discriminator output (9600 bit/s GMSK capable) and would like to feed data 
from your ShipPlotter installation to aprs.fi. Thanks!

   - Hessu, OH7LZB