Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Smaragd
FLYER Club Member  FLYER Club Member
#1827727
This is the problem with all the pro/anti messaging:
Unless the system is reliable (ie. a guaranteed level of performance and also that it is actually switched on!), then really it is not giving a high enough level of confidence for it’s design purpose. There is nothing worse than being mid-air clobbered because the kit on the ground or in the air has let you down.
Today nothing is that reliable - shielding of signals by you or another transmitter, things switched off or absent altogether, SDA=0 preventing the big boys seeing SE2, pilots who are switched off! So at present, and for some time to come (perhaps for ever) I am not expecting that level of confidence. I accept and am grateful for every bit of information for what it is (and PAW has certainly made huge steps since its inception).... but rely on it?
#1827732
neilmurg wrote:It's a shame that some people are choosing SE2 rather than Pilotaware, it denies them the chance if seeing the vast majority of traffic.
Granted that spotting ADSB traffic is much easier, but, that ain't much of the traffic The FLARM (mainly glider) traffic is revealed better at greater distances by ATOM GRID.

SkyDemon offer a £30 subscription to allow the display of FLARM traffic.
By johnm
FLYER Club Member  FLYER Club Member
#1827734
I have concluded that ADS-B and FLARM are the de facto standards and we output certified ADS-B so we're visible to anybody and everybody. I now have Sky Echo 2 in receive only mode and will take out a Skydemon FLARM subscription when aviation picks up again. I will run it alongside a Traffic Service and see what transpires.
#1827740
gaznav wrote:@neilmurg

If you can’t handle the truth about the system’s demonstrable and apparent limitations then please stop ‘spamming’ this discussion :cyclopsani:


@gaznav , once again even though @Cub asked not to start a bun fight - you immediately drift off into stuff and nonsense again :roll:

Lets dispel some of your false claims - not that I think you will take any of this information on board, but where there is life there is hope

gaznav wrote:Just to illustrate. Here is Little Rissington detecting me intermittently before I turn away at 1352:

gaznav wrote:So this is why I believe the reliability is poor and that is one reason why drawing conclusions from Vector is really tricky and likely to make you draw the wrong conclusions. :thumright:


Let me illustrate the reverse situation:
To have an EC 'conversation' two participants are involved, you claim that the intermittent nature of reception is the groundstation - not your EC device, lets put that to the test ...
Here is a diagram of the EC reception from Little Rissington for all EC types
Image

Stunning isn't it :D both in range and capture near to ground level
Let me explain - the rings are spaced at 20km distances, so the outer ring 80km, we trim any 1090 reception from a transponder at 60km MAX, that is why you see the drop off of many signals at the 60km ring. For other EC types there is no such trimming
So as can be seen the performance of EGVL is absolutely stunning, with faultless reception capability
I would also add to this that I am incredibly grateful to the RAF in deciding to equip their airfields with ATOM stations to compliment the GRID network and promote air safety for all.

Coming back to your own issue, looking at your data from VECTOR for your CAP1391 device
Image

I have seen an interesting trend in a number of these device images where there is an emphasis on Emissions, either Front-to-Back, or Left-to-Right, as you can see from yours there is a visible bias from Left-to-Right
Do you still mount your device on the side window ?
The reason I ask is that you previously posted a screenshot of the PCB antenna a while back here
Image

Now I am no expert on antenna theory (I am sure there are others who can comment)
Could the bias be caused by the planar effect of the Antenna, whereby the beam is restricted along the surface plane of the PCB ?
Imagine rotating the PCB through 90 degrees
Could this explain the focusing effect we see where the beam appears greater ?
- Emissions Front-to-Back (EC Device Front/Rear mounted), or
- Emissions Left-to-Right (EC Device Side mounted)

A good experiment would be to dig out your old SkyEcho1 which had an omni-directional dipole antenna
then we could compare/contrast against the data we have collected from your current device

Actually, I think I found one as this says it is emitting SIL=0
Image

I think the blanking to the rear is from the tail rotor section, so that can be discounted, but certainly their is no visible bias either Left/Right or Front/Back - no smoke, no mirrors, simply raw data - but I think we can both see it is significantly better than your plots. and I think the only difference is the antenna type, the underlying electronics is the same I think ?


So in summary, I think EGVL Little Rissington is performing extremely well, as I am sure will the other RAF ATOM stations which are currently in the pipeline
In which case what conclusion would you now like to draw, having been provided with definitive data ?

Thx
Lee
#1827748
I think @gaznav and @neilmurg should get a room.

I also think neither of them help the cause of EC.

They just turn it into a religious war, @neilmurg, do you really think your comments help anyone see PAW in a positive light?

I left the PAW team because I’m interested in EC, not a religious war. Life is too short and I enjoy flying more than electronics.

I’ve used and own both and have made my own decisions.

Guys, stop damaging EC eh?

Oh, and Cub, you knew what you were doing! should have just posted “there are more SE2 than PAW now”. Would have been less inflammatory!
#1827769
@leemoore1966

I totally agree that PWEGVL at Little Rissington is performing very well indeed. But the ones local to me at PWBicester, PWEnstone, PWBanbury, PWEdge (Shennington), PWEGBW (Wellesbourne) and PWNorton all seem to have either no performance (in that they appear switched off!) or they don’t seem to be anywhere near the performance of PWEGVL or PWEGBT (Turweston). It makes me wonder about the ~200 ground stations that are often quoted, just how many are working at peak performance like EGVL or EGBT? If my sample of 15 is anything to go by, then that ~200 goes down to ~100.

As for my polar diagram. It might interest you that during my recent local flights I have barely been more than 20km from EGBT that seems to have provided the vast majority of the position reports. The odd outlier is probably from EGVL as nothing else in the local area seems to pick much up at all! So go figure, the ranges on your Vector diagram are showing mostly inside 20km. :thumright:

Thanks again for staying on the facts of the debate and not sinking to individual name calling. I always enjoy your input. I just wish that others wouldn’t draw some bold and unsubstantiated conclusions on the performances indicated from Vector (as per the recent LAA article).

Yes, mounted on a side window, the same as it is on this Piper Warrior that flies out of Brize. So same device, same mounting orientation but different aircraft type - plus a different ATOM ground station providing the majority of the data. One would also expect the wood/fabric Condor to have less signal attenuation than the all-metal Warrior. I guess they get more hits at range as they stay within detection range of Little Rissington over the Cotswolds for longer. Plus it flies more so has more data points.
Image

A good experiment would be to dig out your old SkyEcho1 which had an omni-directional dipole antenna
then we could compare/contrast against the data we have collected from your current device
I agree, and I will try and ‘rescue’ it from the cabinet at the other airfield when I next visit. :thumright:

Finally, I’m sorry that others are tiring of the debate here, but I think it’s important to discuss such matters to stop some of the “Truth Decay” that appears to go on.

PS. I just noted this one - there is some Truth Decay I’m afraid.
I would also add to this that I am incredibly grateful to the RAF in deciding to equip their airfields with ATOM stations to compliment the GRID network and promote air safety for all.

The RAF are not putting them onto their main airfields. RAF Little Rissington and RAF Topcliffe are airfields run by the Air Cadets and I very much doubt they have had the SCIDA clearances done to allow them to radiate on the airfields. The claim on Linton is false as the airfield closed last year and Leeming doesn’t seem to be operating (probably as it will need SCIDA approval to do so and also TEMPEST (Telecommunications Electronics Materials Protected from Emanating Spurious Transmissions) testing if it is anywhere near classified systems). So really you have a couple of ‘hooky’ installs on Air Cadet gliding sites, that’s all. :thumright:
By Cottie
FLYER Club Member  FLYER Club Member
#1827802
Reception of 1090 ADS-B/Mode S/Cap 1391 devices is not part of the core functionality of the ATOM grid, individual sites not having good reception of 1090 does not indicate that they have weak reception/transmission on their core tasks of Flarm rebroadcast and Mode S broadcast.

The OGN-R stations were originally configured to receive Flarm transmissions and rebroadcast these to Pilotaware. After the up-link of Mode S multilateral data was added, the option of adding an extra receiver to allow OGN-R stations to contribute to 360Radar (for ADS-B and Multilateration) was added.

Not all OGN-R stations have had the extra receiver added, I have yet to swap from the dedicated 360Radar device onto my OGN-R. As the focus is to add more Mode S data to 360Radar some of the stations have probably got the less capable antenna that is perfectly adequate for receiving higher powered Mode S + ADS-B and not as good as receiving lower powered Cap1391.

PWBiceste appears to be a station that has no receiver for 1090 reception, Enstone predates Mode S integration and I suspect has a standard 1090 antenna. Little Rissington being one of the newer stations sould have been fitted with a similar high quality antenna to the Flarm and PAW antennas.

In summary lack of or weak 1090 reception at an OGN-R station is not a weakness in the ATOM grid.
#1827825
johnm wrote:I have concluded that ADS-B and FLARM are the de facto standards and we output certified ADS-B so we're visible to anybody and everybody.

Other than those not suitably equipped. :wink: I wonder what %age that will be as a result of this exercise? :? I'd be interested in knowing that number.
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By Cub
FLYER Club Member  FLYER Club Member
#1827839
leemoore1966 wrote:I would also add to this that I am incredibly grateful to the RAF in deciding to equip their airfields with ATOM stations to compliment the GRID network and promote air safety for all.


@leemoore1966

After hearing Keith announce the deployment of ATOM installations at RAF stations during an online interview, earlier this week, I made some enquiries via the MoD about the rollout schedule for the deployment of these facilities. The person I contacted knew nothing about any such programme. Perhaps you could clarify how many stations are covered by this programme and the timescale to operational service?
User avatar
By Cub
FLYER Club Member  FLYER Club Member
#1827845
Cessna571 wrote:Oh, and Cub, you knew what you were doing! should have just posted “there are more SE2 than PAW now”. Would have been less inflammatory!


I think that is a little unfair. I simply copied the FLYER headline when adding the link to the news item. Trying not to fall foul of RobL’s subject police ;-)
#1827846
@Cottie

Brilliant - thank you. Then we need to stop drawing conclusions like this in the LAA mag - “this is what good looks like”, “this is what average looks like” and “this is what poor looks like”.

Image

It is really misleading to claim that detail on EC performance without understanding which ground station (receiver and antennae set up) has produced the Vector polar diagram and the flight profile of the aircraft. Your helpful post confirms that. :thumright:

By the way, there is another video on YouTube which gives some Electronic Conspicuity details from Keith at Pilot Aware. Worth a watch - the really interesting thing is the announcement of “SkyGrid” that seems to indicate that Pilot Aware will be able to rebroadcast others’ signal akin to JTIDS/Link 16. I’ll be interested to see how this develops.

#1827847
gaznav wrote:Another example, same day, same time. Turweston (PWEGBT) tracks me nicely for most of flights apart from a few PFL practices up near Daventry where I go low(ish) about 15-20nm away:

Image

So this is why I believe the reliability is poor and that is one reason why drawing conclusions from Vector is really tricky and likely to make you draw the wrong conclusions. :thumright:


Gaz,

You are right, you have drawn the wrong conclusion :clown:
You were not tracked nicely for most of the flight as the lower horizontal trace shows that you were not detected for about 1/3 of your flight.

What this does show is the transmission range of your SE2 is quite poor or perhaps your head was blocking the path? :wink:

Anyway, this thread about the rebate scheme which you have hijacked in your never ending crusade to 'repay' uAvionics for the free Sky Echo they gave you :thumright:
#1827849
@Straight Level
Do you know what height I was at the extreme of range near Daventry? No need to be rude either, it’s just churlish.

I also paid £700 collectively for my 2x SkyEchos thanks. :cyclopsani:

PS. Just checked my GPS log and I wasn’t doing PFLs up near Daventry. Sorry. So from the Turweston set up it looks like I was being received at around 20km where it seemed to stop, but the Little Riss one was seeing me intermittently at 40km. So that is the problem - variance in performance with the ground station receiver set up (which Cottie seems to have confirmed).
Last edited by gaznav on Sat Feb 20, 2021 8:07 pm, edited 2 times in total.
#1827854
Cub wrote:
leemoore1966 wrote:I would also add to this that I am incredibly grateful to the RAF in deciding to equip their airfields with ATOM stations to compliment the GRID network and promote air safety for all.


@leemoore1966

After hearing Keith announce the deployment of ATOM installations at RAF stations during an online interview, earlier this week, I made some enquiries via the MoD about the rollout schedule for the deployment of these facilities. The person I contacted knew nothing about any such programme. Perhaps you could clarify how many stations are covered by this programme and the timescale to operational service?


Id be very interested to hear more as well, I was very surprised to hear that a receive / transmission capability connected to the internet had been installed on RAF stations. I do hope the people (clubs?) involved have been through the formal siting board process and have had all the emission clearances done as things might not go well.
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