FlightAware Discussions

Thoughts on FA receiving ADSB data over APRS?


Just wondering what the community and FlightAware’s thoughts are on having Piaware connected to a radio transmitter (with the proper amateur radio license) and transmitting their ADSB Data over the APRS network- FlightAware would have to connect to the APRS network and scrape the data from there.

This would be a very interesting project- then ground stations could be setup in very remote areas where cellular coverage is limited and perhaps be powered by solar and a battery to create something completely off the grid. NOAA does this now with their CWOP program for weather sensing equipment.



Ignoring licensing issues, there is nowhere near enough bandwidth on APRS to be able to relay ADSB. An ADSB message is 112 bits in length so the usual 1200 bd APRS channel would only be able to handle about 5 messages a second on a 50% duty cycle.
I don’t think I ever receive as few messages a second as that. Usually it is well over 1000 messages a second.



With all due respect, I think this is a solution in search of a problem.

Also, FlightAware is a business, and amateur radio cannot be used in this context.



Thanks! The more I think about it, technical and business hurdles aside, my thought was ADSB tracking in more remote areas. These are covered anyway thanks to satellite ADSB tracking now anyway.



If the remote receiver is unable to use cellular it is possibly too remote to use VHF APRS.

Last time I looked about 10 years ago, HF APRS was only 300 bps.

As can be seen here Air Services Australia has considerable ADS-B coverage in the mainly big empty in the middle of Australia. Does the FAA have a similar infrastructure?




The FAA has pretty good coverage


The 5000 ft coverage around Sydney, on the ASA site, looks weird. There doesn’t seem to be coverage around Sydney. I thought YSBK was the busiest airport in the Southern Hemisphere. I would think the training their amd YSSY would warrant decent coverage.



The Air Services page is as at Jan 2017 and at the top it says When operating outside of radar coverage, ADS-B derived ATS surveillance services are provided to operators of aircraft that are ADS-B Out enabled, whilst within the coverage volume of commissioned ADS-B ground stations.

and In airspace where ADS-B coverage overlaps radar coverage, the radar derived aircraft position will be displayed to ATC
Bankstown and Sydney are both within Radar coverage and therefore not included in the red blotches.

According to Wiki Bankstown is only the sixth busiest airport in Australia.

Are all those towers on the Stratux site the infrastructure for UAT?




The towers are infrastructure for UAT and 1090, I believe.

UAT has the advantage of not being spammed with Mode A/C traffic while also providing weather and FIS-B.

I saw recently that Aus may get WAAS/SBAS. This would be nice for precision approaches without the running costs for a full ILS/DME or ILS/Marker installation. Galileo may allow for precision approaches without SBAS(WAAS) or GBAS(LAAS).