978MHz UAT reception on Raspberry pi2B


#1

Can Flightaware/Piaware software also be utilized to track UAT beacons? I have a spare RPI (2B) that could be pressed into service with a second dongle. Think I found dump978 somewhere… not sure though if it works on a RPI2B or not…
Would also have to build a second antenna. :slight_smile:


#2

I have RPi B+ and RPi Model 2.
I have tried UAT978 on both. It works on both Pis.
You will need to install dump978, as dump1090 will not receive 978 Mhz


#3

I loaded dump978 on a second pi/rtl2832 and have it running, however not receiving anything so far using a 1090 antenna. No bandpass filter, so should pick up… something. Might have to wait a while.


#4

UAT 978 is a little tricky. There isn’t much traffic in most places, even NYC is quiet a lot of the time.
Also, there is only one decoder, dump978, that I know of . One amp/filter https://v3.airspy.us/product/upu-fp978s/ and one antenna http://www.dpdproductions.com/page_vhf_air.html#978adsout as the FA Dual band antenna is no longer sold(you can, of course, make your own). I just replaced my FA dual band with the DPD antenna last week. I have the amp and custom ordered some single pole cavity filters last year. I have a lot of cell towers nearby and need the cavity filters.

This is my UAT 978 only feed
http://flightaware.com/adsb/stats/user/jonhawkes2030#stats-20974
I have the DPD antenna feeding a cavity filter, hab amp and rtl-sdr. I also have a directional antenna feeding a cavity filter and Fa Prostick(I think).

Aircraft using UAT typically fly at less than FL180 so your range will be much lower than 1090Mhz. I am also fairly low, <100ft AMSL so don’t have a great range.

If you have another RPI, I suggest setting it up just for UAT978 for testing. It is hard to work out the gain setting as dump978 doesn’t report power levels(at least I haven’t worked out how to do it).It took a lot of trial and error to get it right. Once you are happy, then it can easily feed dump1090 without any problems. It should actually add to your aircraft count.

UAT 978 is only used in the U.S. You look like you may be close enough to the boarder to receive some traffic. Not sure how much you will get though.

PM if you want help.


#5

There are so few airplanes on 978MHz. In the Houston area there are probably a couple dozen UAT planes/day. This is about normal for a major city in the USA.

Most of the problem with detecting UAT aircraft is that they can’t fly above 15,000 feet without also broadcasting 1090MHz ADSB. UAT only planes usually fly below 8000 feet which makes them extremely hard to see if you don’t have the antenna height. This means you “might” have a 50 mile coverage range for UAT.

If you don’t have a high place to put your UAT antenna you will probably be disappointed.


#6

Great info here.
Was finally able to copy two aircraft not long after installing dump978 but none since. Seems very intermittent or short lived. Switched back to using dump1090 and nothing there either and there is lots of traffic around. Was having trouble with this dongle in the past so might be a hardware issue.
Tried running other SDR software that seemed to be working but not getting any audio out of the RPI2B even though I was seeing a signal (strong FM carrier from local FM station) on the waterfall. So might be software too…
Think I should start another SD card with Raspian stretch and start again from scratch in case I messed up somewhere.