Log data analysis results

[DaveReid]

Email sent re evaluation of the Professional version.

[shaun]

Maybe this is related?

[Runway 31]

Nothing related Shaun, just the crew havent done the flight ID for the flight, hence no company logo.

Alan

[shaun]

I can't see what's wrong.

[DaveG]

What is wrong is two things.

First, your issue does not relate to the current discussion in this thread.

Second the reason your not seeing a company logo is because there is no valid FlightID for that record.  Notice it has 0000000, if it had something like RYR1075 then you'd see a RyanAir logo, if BAW95 then a British Airways logo.  The crew of your aircraft have not entered into their system a FlightID.

[DaveReid]

Email sent re evaluation of the Professional version.

My thanks to AirNav for the evaluation copy of RadarBox Professional.

Unfortunately my tests have shown that it, too, suffers from the "hex code confusion" bug (whereby flight details for one aircraft are recorded against a different aircraft whose hex code differs by a few bits). 

An example this afternoon was G-BYAT B752 400573 TOM71E showing details belonging to G-CIVB B744 400551 BAW287.

[malc41]

Dave

Which version of software did this start with?

[malc41]

Dave

Not sure if this is the same problem that you experience?  From todays log

400EBE  GBYWB                    G-BYWI  G115  Vt Aerospace Ltd     2010/05/20 09:05:07 
400EBE  GBYWG                    G-BYWI  G115  Vt Aerospace Ltd     2010/05/20 13:52:29 
400EBE  GBYWI                    G-BYWI  G115  Vt Aerospace Ltd     2010/05/20 13:12:36
also

400EEE  GBYUJ                    G-BYVR  G115  Vt Aerospace Ltd     2010/05/20 14:03:18 
400EEE  GBYVR                    G-BYVR  G115  Vt Aerospace Ltd     2010/05/20 08:17:51

[DaveReid]

Not sure if this is the same problem that you experience?  From todays log

400EBE  GBYWB                    G-BYWI  G115  Vt Aerospace Ltd     2010/05/20 09:05:07 
400EBE  GBYWG                    G-BYWI  G115  Vt Aerospace Ltd     2010/05/20 13:52:29 
400EBE  GBYWI                    G-BYWI  G115  Vt Aerospace Ltd     2010/05/20 13:12:36
also

400EEE  GBYUJ                    G-BYVR  G115  Vt Aerospace Ltd     2010/05/20 14:03:18 
400EEE  GBYVR                    G-BYVR  G115  Vt Aerospace Ltd     2010/05/20 08:17:51

That does indeed look odd, but it's a different issue (probably related to the aircraft database) whereas the bug I'm concerned about relates solely to the data coming from the aircraft (hex code, callsign, squawk, altitude, etc) and isn't related to database lookups.

In answer to your other question about what version of the software the "hex code confusion" bug started with - I have no idea, in fact I'm not even sure whether it's a software or a firmware bug, to be honest.

I could do trials with previous RB versions, but there isn't really much point as most people are on 3.13 or 4.03 now.

[malc41]

Dave

Thanks for that, it was just in the back of my mind that this issue has been around for some time.

[DaveReid]

Thanks for that, it was just in the back of my mind that this issue has been around for some time.

So it would appear - no criticism of the beta-testers intended :-)

To be fair, many enthusiast RadarBox users probably wouldn't be too worried about two aircraft in the list with the same squawk or callsign, or a sudden unexplained jump in altitude (although, as you say, a number of individuals have posted examples).

It's likely to be professional users of RadarBox (and now, it would appear, AirNav Flight Data) who are most affected - the ADS-B application I'm currently working on would certainly be screwed up by, for example, an A320 reappearing at FL380 5 minutes after it has landed, so RadarBox is no longer an option that I'm prepared to offer the client.

Hopefully that will change soon - I would expect that AirNav are reviewing their decoding algorithms even as we speak ...

Dave

[AirNav Support]

Yes we are taking a look at this and will be added to the bugs page.

[tarbat]

I note that on the bug tracking system, you say:
"Occurs mainly in high message areas where Mode-S confusion can occur, mainly as an aircraft lands"

I'm not sure that is true.  Firstly, I'm in an area with low message volumes.  And I've taken port 30003 data, and analysed in Excel.  Out of 45,000 messages, I found two cases of mixed up altitudes.  One aircraft was at FL235 when it suddenly reported an altitude of FL390, and the other was at FL105 when it suddenly reported an altitude of FL390.

In both cases, the ModeS hex codes were different by two bits.
400619 (FL235) vs 400409 (FL390)
010000000000011000011001
010000000000010000001001

400AD1 (FL105) vs 400A99 (FL390)
010000000000101011010001
010000000000101010011001

[DaveReid]

I don't understand the reference to aircraft landing, either.

The bug appears to affect aircraft in all phases of flight, although of course it's easier to spot when there is a wide discrepancy in altitude between the two aircraft, e.g. if one is landing and one is en-route.

[AirNav Support]

Its just related to the ones we have caught during testing. Don't worry its all written down in detail elsewhere.