Primarily for general aviation discussion, but other aviation topics are also welcome.
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By gaznav
#1889507
Now, this one is interesting - Flyer article here: https://www.flyer.co.uk/pilotaware-to-l ... years-day/

It seems that aircraft will be able to rebroadcast aircraft information to others outside of line of sight of a PAW ground station. This is a great development as it removes the reliance on lots of ground stations, and it will be interesting to see how it all works on its roll out on a busy day. Good stuff :thumright:
By SteveX
#1889535
I don't get it. Why would something so far away be of any concern? I don't want to know about anything the other side of a mountain. And if two aircraft were there then they would talk to each other anyway without the need for a ground station, as happens.

Good intention/invention, pointless in the real world.
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By marioair
#1889541
On first reading I agree. If there’s a mountain between me and an a/c do i worry about it ? Need to read into this more.

Will also relay METARS and TAFS? That’s be more useful
By Straight Level
#1889543
Not necessarily a mountain, but if your aircraft is out of range of a ground station and not in receipt of traffic uplink for whatever reason, this will then be relayed from another 'grid' aircraft nearer / in contact with the ground station(s).
So the other 'grid' aircraft would relay info of a close contact, such as Flarm , Mode S-MLAT etc. for example.
So very useful in the real world.
SL
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By russp
FLYER Club Member  FLYER Club Member
#1889544
Very very useful - will relay information on aircraft that are obscured from your aerials for whatever reason but usually because your body or engine is in the way, hopefully will also relay MLAT'd aircraft beyond ground station range that may be very close to you but which you can't see without connection to the atom grid.
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By marioair
#1889570
Sounds like a nice new feature.

However would be interesting to see some stats on number of cases where there was a blind spot of both the other a/c AND a base station AND another a/c happened to be in line of sight that ALSO could see a base station

Having said all of that…..drones …..will change everything.
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By riverrock
FLYER Club Member  FLYER Club Member
#1889572
MLAT, FLARM, OGN are the obvious use cases, which ground stations pick up but PAW doesn't. Now if you are out of range of a base station, but another aircraft is in range, you get the info. Especially when low level, so less likely within range. Will fill in blind spots.
Excellent to hear this is happening. Would be interesting to know if aircraft recievers can feed into MLAT too, so two aircraft and a base station would be able to triangulate MODE-S traffic, but perhaps I'm not asking too much...
Looking forward to the software release!
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By PaulSS
#1889575
@SteveX You're missing the point that there may be other things around, for instance a Flarm equipped glider, that neither ADSB/PAW-equipped aircraft would be able to see but an ATOM station (maybe at the gliding site) can. Once upon a time just the PAW-equipped aircraft within range of the ATOM station would be told about the glider. Now another aircraft, not in range of the ATOM station will get the brief passed on by the in-range machine.

It's not pointless in the real world and will mean a much more comprehensive air picture for any PAW-equipped aircraft.

You get LINK back, Gaz, when you buy a PAW :thumleft:
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By johnm
FLYER Club Member  FLYER Club Member
#1889582
Intriguing. I've been pretty disappointed with my Skyecho2 thus far so might start to think about a change. My slight issue filtering, because it would be good to get rid of anything greater than 5 miles or a thousand feet away to ensure a good quality picture with minimum noise.
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By MattL
#1889592
Fascinating stuff and will be hugely interesting to read more. Does the intermediary aircraft downlink what it has seen to the ground station now then as well I wonder? Or is it just a rebroadcast of any received ground station picture?

I also wonder how they will control multiple daisy chaining / latency in the system, it’s impressive stuff they’ve got so much processing out of the kit.
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By Peter Gristwood
FLYER Club Member  FLYER Club Member
#1889594
I'll be looking to see if this improves the location of Mode C/Mode S aircraft and finally get rid of the 'circles of uncertainty' when PAW detects them
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By gaznav
#1889646
So, I see 2 things that are positive and interesting in recent announcements.

1. The use of aircraft to aircraft passing of information rather than relying on ground infrastructure means that there should be less of a single point of failure to the system. However, as @MattL says, it will be interesting to see how the correlation of aircraft track information from different sources doesn’t generate multiple tracks on a display (or stop displaying the best information information). That was a problem that early JTIDS L16 had to overcome. Sometimes a 4-ship became a 16-24 ship! Achievement of that is really impressive using Raspberry Pi processing.

2. The recent EASA announcement of a common signal format to be used by ~50,000 in use 860 SRD frequency using devices means that there could be just 2 common frequency standards for direct signal detection of each other - this new common 860 SRD EU standard and 1090Mhz ADS-B. So with just 2 signal formats then there could be systems that should be able cooperatively see each other. The only other idea is the 978Mhz “ADS-B Lite” signal standard and also a rebroadcast function. So the race is on really - will 978 or 860 SRD win through. Or will it become a 3 horse race to allow a non-aviation use frequency to be used. I personally believe that the idea of using 4G/5G mobile will fall over.

So my own vision is this - for it to work it needs both systems to do exactly what is required:

1. A 1090/978 MHz ADS-B system that can tx/rx between each other with an ability to see others on the 860SRD either directly or via rebroadcast (like that seen at Goodwood/Lasham and other trials).

2. An 860 SRD common standard that can tx/RX between each other with an ability to see others on 1090/978 MHz ADS-B either directly or via rebroadcast (like ATOM and SkyGRID).

If that comes off, then that would be excellent :thumright:
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By PaulSS
#1889650
How do you think that will happen, Peter?

If an ATOM station is able to transmit Mode S traffic that has been 'triangulated' (MLAT), then the circle will disappear because it is now 'positional' and not just based on signal strength etc. With SkyGrid, that MLAT traffic can be rebroadcast from one aircraft to another (using PAW). If it's just Mode S traffic (because they're too selfish to install something that throws out a position) then you're still just looking at signal strength......unless near an ATOM station or somebody who is rebroadcasting MLAT on that traffic.
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By PaulSS
#1889652
@gaznav No 1 seems pretty simple to solve, just throw out the older signal, that way you don't get multiple tracks and the good signal is more up-to-date. The Beta testing is showing fantastic results and even better when integrated with other news, yet to be released after more testing. I was sceptical but have seen it with my own peepers :thumright:
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By Peter Gristwood
FLYER Club Member  FLYER Club Member
#1889660
PaulSS wrote:How do you think that will happen, Peter?

If an ATOM station is able to transmit Mode S traffic that has been 'triangulated' (MLAT), then the circle will disappear because it is now 'positional' and not just based on signal strength etc. With SkyGrid, that MLAT traffic can be rebroadcast from one aircraft to another (using PAW). If it's just Mode S traffic (because they're too selfish to install something that throws out a position) then you're still just looking at signal strength......unless near an ATOM station or somebody who is rebroadcasting MLAT on that traffic.


I have no idea, as the tech is beyond me. But I was hoping the times I get the red/amber/green circles would reduce - it's good to know there's something about, but not seeing a position isn't all that helpful