Currently, I am running 1090 on Raspberry and 978 on a dedicated play server running Ubuntu.
Question is, do I use the same feeder ID on the 978 as the original(first) 1090? Pros cons?
Next question, on my 978 live data page, I see 60 some aircraft in the PHX, TUC area, but my stats page via FA only shows 2 reported aircraft. What gives?
Also, if I combine the same feeder ID to both systems, I lose MLAT on my 1090.
Each unique running piaware instance should have a different feeder ID.
Michael,
One possible answer. I suspect your location is receiving FAA rebroadcast data from one of the ground sites. This means that your 978 live page is showing the actual 978 aircraft you are receiving, and also FAA rebroadcast data which is a combination of 1090 ads-b, 1090 mode-s, and even 1090 mode-a/c only aircraft based on FAA radar data and FAA mlat.
My location here in Florida is only 3 nm from one of the FAA towers. It looks like a normal communications tower, but broadcasts on both 1090 and 978. Like you, I keep my 1090 and 978 traffic on different computers. That makes it much easier to keep track of. The 1090 system sees rebroadcast data (TIS-B) which is a combination of 978 traffic and mode-s/mode-a/c. The 978 system sees the 978 traffic, and also the rebroadcast traffic. The 978 system also sees the FAA broadcast weather, notams, and other info, but it takes other software to do very much with that.
For me, there is very little 978 traffic, and the range is much shorter due to lower power. It is very common for me to see zero to only a few 978 aircraft, while I will often see clusters of 978 TIS-B rebroadcast traffic appear. Do a search for terms like “TIS’B” and “ADS-R” to get more info.
This link might have dated info, but it is the best known source I have for the FAA rebroadcast tower locations. It looks like there is one on the NW side of Tucson, probably within 10 or so miles of your location. It is up on the same mountain as the “KRQQ FM Tucson” transmitter site, if you do a Google maps search for that.
The tower list was compiled by a hobbyist that wanted to know locations that broadcast 978 MHz FAA weather, notams, and other info receivable by aircraft and used by inflight systems.
FAA tower locations:
http://towers.stratux.me/
There is much more to TIS-B if you are interested. To make it easier to spot, make sure you use the options in “Select Columns” and turn on Data Source. That will confirm if you are receiving it on 1090 or 978.
Regards,
-Dan
This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.