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AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: mighty3507 on May 14, 2009, 09:31:35 PM

Title: Mode-S Flight ID question
Post by: mighty3507 on May 14, 2009, 09:31:35 PM: Hello all,

I have been reading this board for a while now. I finally bit the bullet and purchased a Radar Box. It arrived yesterday and I have been learning and enjoying. I am using the supplied antenna in the attic in our two story house. I might get the antenna outside at some point, but I am pleased with the range so far.

I did have a question. Most of the traffic in the area is Mode-S. While the ADS-B flights have their ID’s and routes displayed, I have yet to see a Mode-S flight have a complete flight ID translation. JetBlue is the only airline I have seen that has at least the flight number displayed ‘37’ or ‘353’ etc. I understand if the crew does not input the flight ID it will not be displayed. However, it seems strange that not one airline inputs the value. So, is this the just the way it is in the U.S. or is it something else? I did attach a screen shot showing what I see in the ‘MyFlights’ listing.

I did find this thread on a Mode-S flight ID issue, but I do not know if is related.
http://www.airnavsystems.com/forum/index.php?topic=1372.0
Thanks,

--Steve in Southern California

[attachment deleted by admin]
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 14, 2009, 09:34:44 PM: V2.10 will fix this, and you'll see FlightIDs on most (maybe not all) ModeS aircraft.
Title: Re: Mode-S Flight ID question
Post by: DaveReid on May 14, 2009, 11:06:22 PM: Quote from: tarbat on May 14, 2009, 09:34:44 PM
V2.10 will fix this, and you'll see FlightIDs on most (maybe not all) ModeS aircraft.

Specifically those which send FlightID as an ELS parameter, which RadarBox currently ignores - it only decodes FlightIDs sent via the ADS-B Identification squitter.
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 06:20:07 AM: Even more specifically, FlightIDs sent in the extended data found in DF20 (Altitude) and DF21 (Squawk) downlink messages.

Example screenshot:

(http://farm4.static.flickr.com/3367/3515305820_7341265420_m.jpg) (http://www.flickr.com/photos/tarbat/3515305820/sizes/o/)
Title: Re: Mode-S Flight ID question
Post by: DaveReid on May 15, 2009, 06:50:12 AM: Quote from: tarbat on May 15, 2009, 06:20:07 AM
Even more specifically, FlightIDs sent in the extended data found in DF20 (Altitude) and DF21 (Squawk) downlink messages.

Indeed so - DF20 and DF21 are the only downlink formats that contain the ELS/EHS parameters.
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 06:59:38 AM: Quote from: DaveReid on May 15, 2009, 06:50:12 AM
Indeed so - DF20 and DF21 are the only downlink formats that contain the ELS/EHS parameters.

That's what testing indicates. DF20/DF21 messages can also contain other data, so RB v2.10 also has to determine whether the data in DF20/DF21 messages actually contain a FlightID and not other data.

This was tested by comparing a days log from RBv2.10 vs. a days log from Planeplotter. There was a close match between aircraft showing FlightID in PP vs. RBv2.10, with just a few discrepancies, likely caused by different reception conditions.

Dave, confirm something for me. Are DF20/DF21 messages only transmitted in response to a ground station, or are they transmitted all the time?
Title: Re: Mode-S Flight ID question
Post by: malc41 on May 15, 2009, 08:03:20 AM: Tarbat

I'm sure that Dave will confirm but my understanding is that DF20/DF21 are only transmitted in response to the UF20/UF21.

UF20 being a request for altitude
UF21 being a rewuest for airframe ID
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 08:24:44 AM: Thanks malc41. Thats also what I suspect, and might explain why sometimes I saw FlightIDs in Planeplotter that didn't appear in RB2.10, and other times they appeared in RB2.10 and not in PP.

Probably depends whether there's an active ModeS radarhead in the locality of the sharer on PP.
Title: Re: Mode-S Flight ID question
Post by: malc41 on May 15, 2009, 08:46:56 AM: Tarbat

Yes its a tricky subject to get the head around. Waiting with fingers crossed for v2.1 and then hopefully the problem will be solved.
Title: Re: Mode-S Flight ID question
Post by: dudbaker on May 15, 2009, 09:03:32 AM: Hi

Remember, requests for data can come from TCAS equipped aircraft as well radar head.

Dudley
Title: Re: Mode-S Flight ID question
Post by: DaveReid on May 15, 2009, 09:12:56 AM: Quote from: malc41 on May 15, 2009, 08:03:20 AM
I'm sure that Dave will confirm but my understanding is that DF20/DF21 are only transmitted in response to the UF20/UF21.

UF20 being a request for altitude
UF21 being a request for airframe ID

Yes - UF20 and UF21 are the extended versions of the standard UF4/UF5 uplinks, which request altitude and squawk respectively.

The difference is that the UF20/UF21 also contains a request for the contents of one of the transponder registers, which are sent in the DF20/DF21 response.

The registers normally requested are:

for ELS:

BDS1,0: Data Link Capability report
BDS2,0: Aircraft Identification (i.e. Flight ID)
BDS3,0: Active TCAS RA(s)

and, for EHS:

BDS4,0: Selected Vertical Intention
BDS5,0: Track and Turn report
BDS6,0: Heading and Speed report
Title: Re: Mode-S Flight ID question
Post by: malc41 on May 15, 2009, 09:51:31 AM: Dave

Where would we be without you ;-)
Title: Re: Mode-S Flight ID question
Post by: Brisbane on May 15, 2009, 11:46:48 AM: On the same tack, is that why Delta never show flight i.d. The only one's that seem to tie-up are the 767-400's.
Title: Re: Mode-S Flight ID question
Post by: DaveReid on May 15, 2009, 12:23:45 PM: Quote from: Brisbane on May 15, 2009, 11:46:48 AM
On the same tack, is that why Delta never show flight i.d. The only one's that seem to tie-up are the 767-400's.

Same reason as above: no ADS-B squitter = no Flight ID (currently) displayed by RB.

The DAL B764s are AFAIK the only ones in their fleet that do have ADS-B, that's why you see their Flight IDs.
Title: Re: Mode-S Flight ID question
Post by: WAL 2T on May 15, 2009, 12:49:45 PM: Another tech question for Dave: I understand from above that the flight id data held in the DF20/21 frames is not currently parsed by the RB software, what about the Mode S only flights which do display a flight id in the current version of the software? are these differences due to different models of transponder? or does this indicate that they have different capabilities?

cheers
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 12:56:54 PM: The military aircraft that only have ModeS but DO display FlightID in the current version of RB appear to transmit their FlightID in a DF17 message.
Title: Re: Mode-S Flight ID question
Post by: DaveReid on May 15, 2009, 01:48:27 PM: Quote from: tarbat on May 15, 2009, 12:56:54 PM
The military aircraft that only have ModeS but DO display FlightID in the current version of RB appear to transmit their FlightID in a DF17 message.

Yes, I've noticed the odd one like that coming up in my monitor, for example AAC Gazelle XX460/43C0CA, with the Identification/Category squitter.
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 02:11:08 PM: Quote from: DaveReid on May 15, 2009, 01:48:27 PM
Yes, I've noticed the odd one like that coming up in my monitor, for example AAC Gazelle XX460/43C0CA, with the Identification/Category squitter.

Like this? FAGIN52, an RAF aircraft.

(http://farm3.static.flickr.com/2288/3533755752_ae768de1d5_o.jpg)

(http://farm3.static.flickr.com/2016/3533760752_3fc231b6d5.jpg) (http://www.flickr.com/photos/tarbat/3533760752/sizes/o/)
Title: Re: Mode-S Flight ID question
Post by: WAL 2T on May 15, 2009, 02:40:05 PM: I take it that the South Western Dash 8 Q400s transmit the fid over the same frame then?
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 02:49:21 PM: I don't think I've ever logged a South Western Dash 8.
Title: Re: Mode-S Flight ID question
Post by: dudbaker on May 15, 2009, 02:52:43 PM: Hi

And these from yesterday.

   Mode S Flight Route Regist Airc Airline Date and Time

   AE284D DEUCE11 2009/05/14 19:08:45
   AE2817 GRIM11 2009/05/14 18:59:25
   AE2863 GATOR21 2009/05/14 13:01:35
   AE2B4E ID 2009/05/14 09:18:05
   AE286D REAPR11 2009/05/14 18:37:15
   AE2803 DEATH21 2009/05/14 18:48:33
   AE286F REAPR14 2009/05/14 09:10:22
   B1AB5E DARK31 2009/05/14 09:25:23
   AE0818 RCH0182 00-0182 C17 USA - Air Force 2009/05/14
   AE10B5 RCH1186 01-0186 C17 USA - Air Force 2009/05/14
   AE178F RUMBL21 01-2001 F15E USA - Air Force 2009/05/14
   AE1174 RCH2102 02-1102 C17 USA - Air Force 2009/05/14
   AE1177 RCH2105 02-1105 C17 USA - Air Force 2009/05/14 0
   AE1178 RCH2106 02-1106 C17 USA - Air Force 2009/05/14 0
   AE117A RCH0185 02-1108 C17 USA - Air Force 2009/05/14 0
   AE117B E21109 02-1109 C17 USA - Air Force 2009/05/14 18
   AE1197 E33114 03-3114 C17 USA - Air Force 2009/05/14 11
   AE1198 E33115 03-3115 C17 USA - Air Force 2009/05/14
   AE119D RCH3120 03-3120 C17 USA - Air Force 2009/05/14
   AE1234 RCH3123 03-3123 C17 USA - Air Force 2009/05/14
   AE1242 RCH024 04-4137 C17 USA - Air Force 2009/05/14
   AE145B RCH399 06-6157 C17 USA - Air Force 2009/05/14 1
   C2B3EB CFC3633 177703 C17 Canada - Air Force 2009/05/14
   AE0686 KOO05 60-0328 K35R USA - Air Force 2009/05/14 1
   AE1265 HKY622 62-1835 C130 USA - Air Force 2009/05/14 1
   AE07B6 QID26 62-3519 K35R USA - Air Force 2009/05/14 2
   AE066D QID10 62-3565 K35R USA - Air Force 2009/05/14 2
   AE12DC HKY20 63-7792 C130 USA - Air Force 2009/05/14
   AE048A GOLD78 63-8008 K35R USA - Air Force 2009/05/14
   AE014C QID11 63-8025 K35R USA - Air Force 2009/05/14
   AE01C9 HAWG95 64-14841 R135 USA - Air Force 2009/05/14
   AE01B3 BURSA40 84-0110 LJ35 USA - Air Force 2009/05/14
   AE01B4 HOOK63 84-0111 LJ35 USA - Air Force 2009/05/14
   AE07E3 RCH192 94-0069 C17 USA - Air Force 2009/05/14
   AE07EA RCH106 95-0107 C17 USA - Air Force 2009/05/14
   AE17BE HOWLR12 98-0134 F15E USA - Air Force 2009/05/14
   AE0806 RCH292 99-0060 C17 USA - Air Force 2009/05/14
   AE0807 B H 99-0061 C17 USA - Air Force 2009/05/14
   43C0A5 RRR 9202 XR808 VC10 UK - Air Force 2009/05/14
   43C0A7 RRR2108 XV105 VC10 UK - Air Force 2009/05/14
   43C0A8 RRR2062 XV107 VC10 UK - Air Force 2009/05/14
   43C12D RRR 673 XV221 C130 UK - Air Force 2009/05/14
   43C204 KRF17 ZD704 H25B UK - Air Force 32... 2009/05/14
   43C1C1 ISE32HC ZD950 L101 UK - Air Force 2009/05/14
   43C3A0 9IE ZH102 E3CF UK - Air Force 2009/05/14
Title: Re: Mode-S Flight ID question
Post by: WAL 2T on May 15, 2009, 02:58:41 PM: Hi Tarbat, I did mean Air Southwest, apologies

40079F WOW306A G-WOWA DH8C Air Southwest 2009/05/14 19:16:26
40079D WOW303A G-WOWE DH8C Air Southwest 2009/05/14 18:05:45
Title: Re: Mode-S Flight ID question
Post by: tarbat on May 15, 2009, 03:26:46 PM: Quote from: WAL 2T on May 15, 2009, 02:58:41 PM
Hi Tarbat, I did mean Air Southwest, apologies
40079F WOW306A G-WOWA DH8C Air Southwest 2009/05/14 19:16:26
40079D WOW303A G-WOWE DH8C Air Southwest 2009/05/14 18:05:45

Okay, I haven't seen an Air Southwest flight since last year. However, I see plenty of Flybe and Wideroe Dash 8 402Q's, and these are all now showing FlightIDs in v2.10.

Here's an example on screen now:

(http://farm3.static.flickr.com/2232/3533073771_5e4c1eca8d.jpg) (http://www.flickr.com/photos/tarbat/3533073771/sizes/o/)
Title: Re: Mode-S Flight ID question
Post by: DaveReid on May 15, 2009, 03:31:50 PM: Quote from: WAL 2T on May 15, 2009, 02:40:05 PM
I take it that the South Western Dash 8 Q400s transmit the fid over the same frame then?

I would assume so, although with SBS it's impossible to tell whether the Flight ID is coming from the Extended Squitter or the ELS DAPs without capturing the message packets.
Title: Re: Mode-S Flight ID question
Post by: mighty3507 on June 28, 2009, 03:43:12 AM: Just a quick update. I have been running 3.0 beta since it was released. I was hoping to see a lot more flight ID's for Mode-S flights. I have seen a slight improvement. (Flight ID's show frequently for Air Canada and U.S. Airways). Overall, just not the increase I had hoped for.

Attached is a screen shot of what I typically see. It is safe to say that the missing flight ID's are just not being input by the flight crews or is it there something RadarBox can do to pick these up?

---Steve
Chino Hills, Calif.
DPD antenna located in the attic
Title: Re: Mode-S Flight ID question
Post by: tarbat on June 28, 2009, 07:02:42 AM: It could also be the there's not a ModeS radarhead nearby to send the request. Explanation at http://www.kinetic-avionics.co.uk/forums/viewtopic.php?p=29693#29693
Title: Re: Mode-S Flight ID question
Post by: AirNav Development on June 28, 2009, 09:01:23 AM: mighty3507: V3.0 decodes all possible mode-s frames containing flight Id information. So if you don't see them, then it is a matter of improving you reception conditions.
Title: Re: Mode-S Flight ID question
Post by: DaveReid on June 28, 2009, 10:22:29 AM: Quote from: AirNav Development on June 28, 2009, 09:01:23 AM
So if you don't see them, then it is a matter of improving you reception conditions.

But see also Tarbat's post above.

If an aircraft that you're picking up doesn't have 1090ES and it's not within range of a Mode S interrogator, then you're not going to see Flight IDs for it, period - no matter how good your reception is.
Title: Re: Mode-S Flight ID question
Post by: Allocator on June 28, 2009, 10:50:03 AM: I'm fairly sure that I'm getting more Flight ID's vith V3.0 Beta - although this is a pretty poor example as 3 of the DH8D's are not showing ID.
Title: Re: Mode-S Flight ID question
Post by: DaveReid on June 28, 2009, 11:21:17 AM: Quote from: Allocator on June 28, 2009, 10:50:03 AM
I'm fairly sure that I'm getting more Flight ID's vith V3.0 Beta - although this is a pretty poor example as 3 of the DH8D's are not showing ID.

You're unlikely to get a Flight ID for 400930/G-JEDK - for some reason it started sending nulls in this field about 3 years ago, and it's still doing it.