FlightAware Discussions

Traffic on 978 and 1090

Hello everybody

I activated the 978 and 1090 with 3.7.1 software.
The count is low on the 978 which I expected, but
I occasionally see the same aircraft on both 1090 and 978.
Do you think they have both systems onboard?
I clicked on them and the are both showing as being tracked by ADS-B
Anyway just though it was interesting.


If I had an aircraft of my own I would want both systems.
1090 for International flight and 978 for FIS-B and weather.

There are many times, at remote or isolated airports, when an aircraft would not be in range of ADS-B towers to receive TIS-B information.

There are a few models that do both. It is not cheap and would depend on how and where you fly.

FAA ground stations rebroadcast data onTIS-B. Look at the listing on the right of Skyview. The color will tell you the data source.

Is there a way to identify which (or where) the tis-b signal is originating from… ? All is see is the italic icao numbers which I think is a ‘radar track’ number.

In the underlying messages there is a TIS-B site ID (just a number), but skyview doesn’t show that and it may be hard to turn that ID into anything useful anyway, IIRC there are only 15 (?) site IDs so they’re not globally unique.

However, the trackfile identifiers that the FAA uses do follow a pattern - the first three digits identify the original source of the data - there is a list floating around somewhere but unfortunately I can’t find it right now.

For 1090MHz ADS-B rebroadcast on 978MHz, these generally show up as TIS-B with a proper ICAO address.

The ground site broadcasting the TIS-B message has to be fairly close. (Line of site and all with a ground transmitter) The FAA has a map on their site bit won’t put out a list.

Here is an unofficial map


I often see aircraft with both UAT and ADSB, likely due to cross-border flights. One local Canadian carrier as a couple of smaller commuter planes that use both, often see them between YWG and GFK.
UAT traffic is increasing and interesting to see them. Just watched a plane that left Fargo going west where I lost him at a range of 176NM but he was at 24000ft. Have a tree in that direction that likely blocks the signal somewhat. A lot of UAT traffic often in the 6000ft range; I usually get them to 100NM or better sometimes.
Would be nice to see TIS-B data show up on the 978 SkyView map too, maybe a special icon for the airport you can click on to see their latest metar data etc. :slight_smile: I do see data from Crookston once in a while.

Weather is part of FIS-B not TIS-B.

There would need to be an aircraft, in range, transmitting on UAT978 to receive the FIS-B weather information.

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Yes I have trouble with acronyms… :slight_smile:
Thank you for the link, that explains things a bit better.
One of these days I’ll have to take ground school so I have an idea how all this stuff works. Problem is then I’ll want to do the flight training and end up with a license…then I have to buy a plane… I just don’t have time for all that…

Are others willing to share their 1090 to 978 ratios? On just a two day sampling (screenshots below), my ratio is 50 to 100 to one, 1090/978. I’m located 35 miles west of Houston.


Top table: Site 105801 1090 ES
Botom table: Site 107621 978 UAT

I don’t have separate feeders but here’s what i’ve seen in the last 48hours. Located <40 miles SE of Cleveland (between KCAK and KAKR). Not as much UAT traffic as I was hoping. Antenna is inside. Still working on gain and antenna placement so I would hope it improves! :grin:


Hey @jamieshore7 here’s a sample from my home installation a bit east of you:



That ratio of 1-uat to 100-1090MHz seems to say the FAA January 2020
mandate for ads-b position electronic is not going to be met by a large number
of general aviation planes.

My site is greater then 100nm from a class C airspace, but there is a LOT of
traffic that does not broadcast 1090 or 978.

I wonder what ‘waivers’ the controllers will be issuing after January 2020.

edit: fyi my sites are 101278 (1090) and 101884 (978)
Screenshot_2019-09-01%20ac8dg%20ADS-B%20Feeder%20Statistics%20%E2%9C%88%20FlightAware Screenshot_2019-09-01%20ac8dg%20ADS-B%20Feeder%20Statistics%20%E2%9C%88%20FlightAware(1)

NYC 978Mhz


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Are those real airplanes, or does this include a boat-load of TIS-B? My counts are roughly a third of yours but they include lot of TIS-B I suspect

Three major and a few minor airports in the area. It probably includes a lot of TIS-B.
There is a major VFR corridor down the Hudson river, that includes quite a few tourist helos and visiting airplanes.