Spike question

[bratters]

I've had a couple of 250-300nm spikes for some months and I noticed that occasionally they show signs of slight changes but I was never sure whether these were genuine or not.

Today for the first time I spotted a flight on the outer extent of one of these spikes and was able to take a screenshot (attached). The flight subsequently disappeared completely.

Any suggestions?

[bratters]

By the strangest coincidence, I've also got activity today on my second pre-existing spike. pic attached.

I know the flight concerned enjoys a reputation for rubbish position info. but why should these two particular geographical points be so favoured? They are the only spikes I have and they've both been up and running for at least three months.

[DaveReid]

I know the flight concerned enjoys a reputation for rubbish position info. but why should these two particular geographical points be so favoured? They are the only spikes I have and they've both been up and running for at least three months.

There was a long thread on this aircraft (which is G-OOAF, by the way, not G-JEMB) back in January.

www.airnavsystems.com/forum/index.php?topic=4170.0

In fact it doesn't send rubbish positional info, or indeed any positional info at all, as it doesn't have ADS-B. 

It only plots on the map due to a decoding bug, specific to RadarBox, for which I posted a suggested fix six months ago ...

[bratters]

I know the flight concerned enjoys a reputation for rubbish position info. but why should these two particular geographical points be so favoured? They are the only spikes I have and they've both been up and running for at least three months.

There was a long thread on this aircraft (which is G-OOAF, by the way, not G-JEMB) back in January.

www.airnavsystems.com/forum/index.php?topic=4170.0

In fact it doesn't send rubbish positional info, or indeed any positional info at all, as it doesn't have ADS-B. 

It only plots on the map due to a decoding bug, specific to RadarBox, for which I posted a suggested fix six months ago ...

Thanks Dave. Very interesting.

I seem to recall all sorts of forum spike theories including microwave interference. However in view of your comments maybe the co-ordinates of my two spikes are in some way "bug-related"?

If that is the case and spikes are therefore not peculiar to indvidual PCs, then logically others will have identical spikes to mine.

Any takers out there?

[eggplant]

Snap !

[DaveReid]

Snap !

And, as has been previously noted, should you chance to look at the screen when the aircraft in question is being picked up, you will see that the "position" is being reported as N 48 00 00 E 000 00 00 (a few miles west of Le Mans).

That's the decoding bug in action - any progress on a fix, AirNav ?

[bratters]

And, as has been previously noted, should you chance to look at the screen when the aircraft in question is being picked up, you will see that the "position" is being reported as N 48 00 00 E 000 00 00 (a few miles west of Le Mans).

That's the decoding bug in action - any progress on a fix, AirNav ?

Can we assume then that similar "position reports" are responsible for the second spike activity in the North Sea off Fraserburgh in the vicinity of N 58 00 E 000 00?

[tarbat]

Can we assume then that similar "position reports" are responsible for the second spike activity in the North Sea off Fraserburgh in the vicinity of N 58 00 E 000 00?

I don't have that particular one in my log, although I do have:
34158E (EC-ICA) at N12 00.0 E000 00.0

Others are listed at http://www.airnavsystems.com/forum/index.php?topic=2350.msg19838#msg19838

A useful technique is to export your MyLog/Flights table, and then search for the text "000 00.0".

[DaveReid]

Can we assume then that similar "position reports" are responsible for the second spike activity in the North Sea off Fraserburgh in the vicinity of N 58 00 E 000 00?

I would imagine so, although that one's slightly unusual as the spurious latitudes are usually an integer multiple of 6 degrees, which it isn't in this case.

[orkney]

hello

What is the actual information that the non ADS-B  ATPs transmit to make radarbox think that they are positions since no other aircraft seem to cause this problem?

Andrew

[DaveReid]

What is the actual information that the non ADS-B  ATPs transmit to make radarbox think that they are positions since no other aircraft seem to cause this problem?

I vaguely recall posting details of the aircraft transmissions in question, along with my suggested fix, back in January - but I can't find the relevant message via the forum search, and AirNav's subsequent inaction doesn't make me feel inclined to spend too much time looking for it :-)

Tarbat's example was a Dash 8, by the way, so it's not just ATPs.

[eggplant]

http://www.airnavsystems.com/forum/index.php?topic=4170.0

Here it is !

Maybe Airnav would like to comment. I am sure they are not proponents of the "let's ignore the problem and hope it goes away" school of thinking.

[eggplant]

http://www.airnavsystems.com/forum/index.php?topic=4444.15

In this thread Dave states "AirNav: I would strongly question the wisdom of displaying decoded coordinates where the NUC_P is 3 and the CPR encoded longitude is all zeroes - that's what the invalid packets from the above aircraft appear to have in common."

Airnav replied "It is being investigated and details have been passed to our development team" on 3rd March.

Airnav can you inform us of your development teams conclusion ?

Thanks

[DaveReid]

Airnav replied "It is being investigated and details have been passed to our development team" on 3rd March.

Airnav can you inform us of your development teams conclusion ?

To be fair to AirNav, I suspect they have their hands rather full at the moment.

As well as the Spurious Position bug, which hopefully is still being worked on, they have also undertaken to investigate the Hex Code Confusion bug, the Flight Merging bug and the Equatorial Black Hole bug.  And that's on top of the development of RadarBox MLat and the project to get the new aircraft database architecture up and running.

But I agree it would be useful to have a heads-up re the relative priority being given to each of these and estimates of the likely timeline for rectification/release as appropriate.

The "we'll tell you when we tell you" record is beginning to get a bit worn out - come on AirNav, status update on all the above, please !

[DaveReid]

come on AirNav, status update on all the above, please !

Oh dear ...

Three days on, no response presumably means no progress on any of those bug-fixes ....

Any other forum members developing professional applications using RadarBox ?  If so, have you managed to find workarounds for all or any of the above bugs ?  PM me if you have, it would be much appreciated.

MTIA
Dave