AirNav Systems Forum

AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: DaveReid on June 19, 2009, 07:59:58 AM

Title: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 19, 2009, 07:59:58 AM
I've started a separate thread for this, although it's also relevant to the Future Developments thread given the stated aim of providing compatibility with the corresponding SBS/BaseStation socket output, so that applications designed for the latter will also work seamlessly with RadarBox.

Firstly, examples of the current output (spacing added to improve legibility):

Code: [Select]
RadarBox:
MSG,3, 0,  0,4006B3,      0,2009/06/19,06:15:05.984,2009/06/19,06:20:05.984,,18225,390,097,51.4870,-1.9225,-2432,4244,0,0,0,0
MSG,1, 0,  0,4006B3,      0,2009/06/19,06:15:17.421,2009/06/19,06:20:17.421,BAW4J,17750,381,097,51.4854,-1.9028,-2496,4244,0,0,0,0
MSG,3, 0,  0,4006B3,      0,2009/06/19,06:22:06.140,2009/06/19,06:27:06.140,BAW4J,16000,365,090,51.3102,-0.8433,0,4244,0,0,0,0
MSG,3, 0,  0,4006B3,      0,2009/06/19,06:22:22.406,2009/06/19,06:27:22.406,BAW4J,15875,360,091,51.3098,-0.8001,-448,4244,0,0,0,0
MSG,3, 0,  0,4006B3,      0,2009/06/19,06:22:32.171,2009/06/19,06:27:32.171,BAW4J,15800,357,091,51.3095,-0.7739,-576,4244,0,0,0,0
MSG,3, 0,  0,4006B3,      0,2009/06/19,06:22:46.031,2009/06/19,06:27:46.031,BAW4J,15700,357,091,51.3090,-0.7430,-576,4244,0,0,0,0
MSG,3, 0,  0,4006B3,      0,2009/06/19,06:24:31.562,2009/06/19,06:29:31.562,BAW4J,15000,321,091,51.3056,-0.4856,0,4244,0,0,0,0

SBS/BaseStation:
AIR,,64,522,4006B3,1509068,2009/06/19,07:12:42.179,2009/06/19,07:12:42.179
SEL,,64,522,4006B3,1509068,2009/06/19,07:12:42.945,2009/06/19,07:12:42.945,BAW4J
ID ,,64,522,4006B3,1509068,2009/06/19,07:12:42.992,2009/06/19,07:12:42.992,BAW4J
MSG,1,64,522,4006B3,1509068,2009/06/19,07:17:51.870,2009/06/19,07:22:52.273,BAW4J,,,,,,,,,,,
MSG,5,64,522,4006B3,1509068,2009/06/19,07:17:51.870,2009/06/19,07:22:52.273,,16025,,,,,,,0,,0,0
MSG,4,64,522,4006B3,1509068,2009/06/19,07:17:52.089,2009/06/19,07:22:52.273,,,365.7,105.7,,,0,,,,,
MSG,5,64,522,4006B3,1509068,2009/06/19,07:17:52.089,2009/06/19,07:22:52.273,,16025,,,,,,,0,,0,0
MSG,6,64,522,4006B3,1509068,2009/06/19,07:17:52.089,2009/06/19,07:22:52.089,,16000,,,,,,4244,0,0,0,0
MSG,3,64,522,4006B3,1509068,2009/06/19,07:17:52.089,2009/06/19,07:22:52.273,,16025,,,51.36583,-1.52344,,,0,0,0,0
MSG,8,64,522,4006B3,1509068,2009/06/19,07:17:52.089,2009/06/19,07:22:52.273,,,,,,,,,,,,0
MSG,5,64,522,4006B3,1509068,2009/06/19,07:17:52.495,2009/06/19,07:22:53.273,,16025,,,,,,,0,,0,0
MSG,4,64,522,4006B3,1509068,2009/06/19,07:17:52.495,2009/06/19,07:22:53.273,,,365.8,105.2,,,0,,,,,

And here's a somewhat edited/updated version of the documentation on the socket output format from the sticky on the Kinetic forum:

Four types of messages are currently output. They are:

NEW AIRCRAFT MESSAGE

This message is broadcast when the SBS-1 picks up a signal for an aircraft that it isn't currently tracking, i.e. it's when a new aircraft appears on the right-hand aircraft list.

It doesn't mean new aircraft in the sense of an aircraft that wasn't previously in the database.

Field 1: AIR
Field 2: [null]
Field 3: System-generated SessionID
Field 4: System-generated AircraftID
Field 5: HexIdent
Field 6: System-generated FlightID (N.B. not callsign)
Field 7: Date message generated
Field 8: Time message generated
Field 9: Date message logged
Field 10: Time message logged

Because this is a real-time message, fields 7/9 and 8/10 will have the same value.


ID MESSAGE

This message is broadcast when a callsign is first received, or changes.

Field 1: ID
Field 2: [null]
Field 3: System-generated SessionID
Field 4: System-generated AircraftID
Field 5: HexIdent
Field 6: System-generated FlightID
Field 7: Date message generated
Field 8: Time message generated
Field 9: Date message logged
Field 10: Time message logged
Field 11: Callsign

Because this is a real-time message, fields 7/9 and 8/10 will have the same value.


SELECTION CHANGE MESSAGE

This is broadcast when the user changes the selection, although because of the way the grid works, it is possible that this might also fire when new aircraft are added (with the values staying the same).

Field 1: SEL
Field 2: [null]
Field 3: System-generated SessionID
Field 4: System-generated AircraftID
Field 5: HexIdent
Field 6: System-generated FlightID
Field 7: Date message generated
Field 8: Time message generated
Field 9: Date message logged
Field 10: Time message logged
Field 11: Callsign

Because this is a real-time message, fields 7/9 and 8/10 will have the same value.

Flight ID is the database ID of the record for the flight that the aircraft is currently making.

 
TRANSMISSION MESSAGE

This is basically a delayed (5 minutes) outputting of every message received from the aircraft.

Field 1: MSG
Field 2: Transmission Type
Field 3: System-generated SessionID
Field 4: System-generated AircraftID
Field 5: HexIdent
Field 6: System-generated FlightID
Field 7: Date message generated
Field 8: Time message generated
Field 9: Date message logged
Field 10: Time message logged
Field 11: Callsign
Field 12: Altitude
Field 13: GroundSpeed
Field 14: Track
Field 15: Lat
Field 16: Long
Field 17: VerticalRate
Field 18: Squawk
Field 19: Alert
Field 20: Emergency
Field 21: SPI
Field 22: IsOnGround

However, it gets a bit more complicated, as you will see if you look in the log files, because not all messages set all fields. Basically, you have to look at field 2, the TransmissionType. This can have the following values:

1 = ID Message (1090ES DF17 or ELS DAP)
2 = Surface Position Message (1090ES DF17)
3 = Airborne Position Message (1090ES DF17)
4 = Airborne Velocity Message (1090ES DF17)
5 = Surveillance Altitude Message (DF4, DF20)
6 = Surveillance ID (Squawk) Message (DF5, DF21)
8 = All-Call Reply/TCAS Acquisition Squitter (DF11)

These messages have values in the following fields:

IDMessage: Callsign
Surface Position Message: Altitude, GroundSpeed, Track, Lat, Long
Airborne Position Message: Altitude, Lat, Long, Alert, Emergency, SPI
Airborne Velocity Message: GroundSpeed, Track, VerticalRate
Surveillance Altitude Message: Altitude, Alert, SPI
Surveillance ID (Squawk) Message: Altitude, Squawk, Alert, Emergency, SPI
All-Call Reply: None at the moment


Over to you, AirNav !
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: malc41 on June 19, 2009, 08:10:21 AM
Dave

Very interesting, thanks for the info.

This is what makes the forum what it is.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on June 19, 2009, 08:27:36 AM
Dave, this is more or less the same information I provided to A@Airnav back in March 2008.  Back then we ended up with a compromise of getting it working for Planeplotter and sbsplotter, just using MSG 3.

My recommendation at the time was as follows:

Quote
We all know that the output on port 30003 is not complete.  Yes, Transmission Type 3 messages look okay, although many messages output as type 3 are NOT really type 3 – this one for example (it has no position data):
MSG,3,0,0,C058B0,0,2008/03/06,10:39:13.669,2008/03/06,10:44:13.669,ACA869,32975,,,0,0,0,,0,0,0,0

Looking at port 30003 output, I think all transmission types are being output, but they’ll all being marked as type 3.  You’ll need to output all transmission types if you’re going to get SBS addons working:
1=IDMessage: Callsign
2=SurfacePositionMessage: Altitude, GroundSpeed, Track, Lat, Long
3=AirbornePositionMessage: Altitude, Lat, Long, Alert, Emergency, SPI
4=AirborneVelocityMessage: GroundSpeed, Track, VerticalRate
5=SurveillanceAltMessage: Altitude, Alert, SPI
6=SurveillanceIDMessage: Altitude, Squawk, Alert, Emergency, SPI
7=AirToAirMessage: Altitude

I’d suggest a release note that states that the framework is now in place to output on port 30003, and that Transmission Type 3 messages have been tested.  Other Transmission Types should be developed over the next few weeks.  Maybe ask users which addons are important to them, so they can be tested.

Its frustrating that over a year later, we're still not nearer to a fully compliant port 30003 output.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 19, 2009, 08:58:54 AM
Its frustrating that over a year later, we're still not nearer to a fully compliant port 30003 output.

Quite so.

For example I understand that an add-on application like Squawkbox has to handle RadarBox and SBS socket outputs differently, because BaseStation outputs the squawk in a MSG 6 whereas RadarBox sticks it in a MSG 3.

It's also very misleading to output all the 1090ES/ELS parameters in every MSG 3, because the aircraft never sends, for example, groundspeed and altitude in the same transmission, ditto squawk and vertical rate, etc.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on June 19, 2009, 09:07:25 AM
For example I understand that an add-on application like Squawkbox has to handle RadarBox and SBS socket outputs differently, because BaseStation outputs the squawk in a MSG 6 whereas RadarBox sticks it in a MSG 3.

But Squawkbox is pretty useless on a 5-minute delayed output anyway (sorry Andy).  And that's my overall point - Airnav need to understand what users want to use the port 30003 output for.  Many of the addons for the SBS-1 rely on a real-time port 30003 output, and that's never going to be available in Radarbox.

For example, Dave, what do you want to use the port 30003 output for?
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 19, 2009, 10:11:37 AM
For example, Dave, what do you want to use the port 30003 output for?

The answer's still the same as yesterday  :-)

www.airnavsystems.com/forum/index.php?topic=2885.msg25845#msg25845
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on June 19, 2009, 10:24:52 AM
The answer's still the same as yesterday  :-)

www.airnavsystems.com/forum/index.php?topic=2885.msg25845#msg25845

Can't you achieve that with the current port 30003 output from RB?  All the data is there, isn't it?
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 19, 2009, 10:41:14 AM
Can't you achieve that with the current port 30003 output from RB?  All the data is there, isn't it?

Yes, of course it is, if only I could be bothered to rewrite my capture application so that it expects the MSGs in RadarBox format rather than BaseStation format (GS/track in MSG 4, squawk in MSG 6, etc).  But the point is that this shouldn't be necessary, the formats should be the same.

Incidentally I've never shared the view that the 5-minute delay renders the socket output useless. It's never been an issue with the LHR site and I've also been running an alerting application for OTTs for the last 3 years which reads the delayed output and simply uses DR to predict the aircraft's position in 5 minutes time (i.e. now).  I'd say that on 99% of the occasions that my BlackBerry pings to tell me there's an interesting aircraft overhead, I look up and there it is.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: OKC-Steve on June 19, 2009, 11:34:00 AM
RB also has integers where SBS has floats.  ground track and ground speed should be floats of 1 decimal point accuracy.  I don't know about the current version, but the last version the booleans at the end were always false.

Code: [Select]
[0] MSG
[1] 3
[2] 0                  (Session ID not used)
[3] 0                  (Aircraft ID not used)
[4] ACID               (Hex ID)
[5] 0                  (FlightID not used)
[6] Date Detected      (YYYY/MM/DD)
[7] Time Detected      (HH:MM:SS.mmm)
[8] Date Sent          (YYYY/MM/DD)
[9] Time Sent          (HH:MM:SS.mmm)
[10] Callsign          (String)
[11] Altitude          (Integer)
[12] Groundspeed       (Integer)
[13] Groundtrack       (Integer}
[14] Lat               (Float)
[15] Lon               (Float)
[16] Vertical Rate     (Integer)
[17] Squawk            (octal Integer)
[18] Alert             (Boolean) always false
[19] Emergency         (Boolean) always false
[20] SPI               (Boolean) always false
[21] OnGround          (Boolean) always false

Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 19, 2009, 11:47:17 AM
RB also has integers where SBS has floats.  ground track and ground speed should be floats of 1 decimal point accuracy.

And I though I was picky    :-)

The E-W and N-S velocity components are only encoded at 1kt resolution, so I wouldn't put too much faith in those tenths of knots and degrees !
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Andy Frost on June 19, 2009, 06:36:08 PM
To reply to Tarbat, totally agree, a 5 minute delay makes SquawkBox fairly useless. I was led to believe that live data would be output by the new version without positional information. See reply to jgrloit on http://www.airnavsystems.com/forum/index.php?topic=2139.15 (http://www.airnavsystems.com/forum/index.php?topic=2139.15). I can't see this addition in the "Official full list of suggestions/improvements" for version 3.0 so I guess it got missed.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: jmhayes on June 19, 2009, 09:01:15 PM
I don't know about the current version, but the last version the booleans at the end were always false.
I haven't seen any change in this in v3.0 ...
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: jmhayes on June 19, 2009, 09:03:19 PM
I've never shared the view that the 5-minute delay renders the socket output useless
I totally agree with Dave: the data is useful even if not in real-time.

I saw a message today that was interesting:
Code: [Select]
MSG,1,0,0,A6A114,0,2009/06/19,01:58:12.984,2009/06/19,02:03:13.000,VRD757,12100,
374,160,38.0032,-122.7191,-1920,,0,0,0,0
Note that the detected/sent times aren't exactly 5 minutes apart :D
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: jmhayes on June 20, 2009, 03:40:26 PM
One thing to watch out for that I just noticed: under certain circumstances, you can get duplicate rows: I've only seen this a few times now, but certain aircraft seem to trigger it.  And it's not every message: just some!  I don't see anything else binding them together, so if that matters to you, watch out.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Harry on June 28, 2009, 11:57:58 AM
I have been away for a few months from this forum and I cannot find the answer in all the messages with the release of Beta 3: is airnav going to do something about the socket output or not?
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 28, 2009, 12:32:26 PM
I have been away for a few months from this forum and I cannot find the answer in all the messages with the release of Beta 3: is airnav going to do something about the socket output or not?

As far as I can see, there's no change to the socket output in the 3.0 Beta, so it would seem unlikely that it's going to be in the released version.

But given that AirNav have been asking detailed questions about the format, and about its incompatibility with the SBS spec that it's supposed to be emulating, I'm reasonably optimistic that it will be addressed at some stage.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Fenris on June 28, 2009, 12:39:23 PM
I thought that it was supposed to be modified to only time delay positional messages, not those without position information.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 28, 2009, 12:44:10 PM
I thought that it was supposed to be modified to only time delay positional messages, not those without position information.

That was certainly suggested, but I don't recall any undertaking being made to implement it.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: jmhayes on June 28, 2009, 03:32:42 PM
As far as I can see, there's no change to the socket output in the 3.0 Beta, so it would seem unlikely that it's going to be in the released version.
I think the big change between v2.1 and v3.0 is that the non-positional aircraft are finally available.  It's still kind of a curious mess, but it's way better than it was.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on June 28, 2009, 04:24:51 PM
I think the big change between v2.1 and v3.0 is that the non-positional aircraft are finally available.  It's still kind of a curious mess, but it's way better than it was.

You're absolutely correct, I hadn't picked up on that.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Fenris on June 28, 2009, 04:55:06 PM
As far as I can see, there's no change to the socket output in the 3.0 Beta, so it would seem unlikely that it's going to be in the released version.
I think the big change between v2.1 and v3.0 is that the non-positional aircraft are finally available.  It's still kind of a curious mess, but it's way better than it was.

And are these non-positional aircraft records 5 min delayed or not?
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: jmhayes on June 28, 2009, 04:58:55 PM
are these non-positional aircraft records 5 min delayed or not?
All data on port 30003 is 5-minute delayed in v3.0 beta.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Fenris on June 28, 2009, 05:00:51 PM
OK, so that will break Squawkbox then...
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on June 28, 2009, 05:49:29 PM
OK, so that will break Squawkbox then...

Squawkbox works okay with v3.0, albeit 5-min delayed.  Maybe this might get implemented - http://www.airnavsystems.com/forum/index.php?topic=1284
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Harry on July 02, 2009, 09:57:32 AM
Thanks for the feedback.

Is it me or are only hexcodes with call signs on the port output?

Harry


I think the big change between v2.1 and v3.0 is that the non-positional aircraft are finally available.  It's still kind of a curious mess, but it's way better than it was.

You're absolutely correct, I hadn't picked up on that.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on July 02, 2009, 09:59:53 AM
I get aircraft without callsigns on port 30003, using v3.0 beta.  Maybe not in v2.0
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Harry on July 02, 2009, 10:10:27 AM
I get aircraft without callsigns on port 30003, using v3.0 beta.  Maybe not in v2.0

Ok. thanks. I'm looking at port 7879 right now, so maybe there is a differance.

Harry
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on July 02, 2009, 10:47:15 AM
Are you running v2.0 or v3.0 beta.  Looking at port 7879, I also see aircraft without callsigns/FlightIDs.

EG:
<MODESMESSAGE>
  <DATETIME>20090702103928</DATETIME>
  <MODES>A8BD53</MODES>
  <ALTITUDE>10700</ALTITUDE>
  <VRATE>0</VRATE>
  <AIRSPEED>000</AIRSPEED>
  <LATITUDE>0</LATITUDE>
  <LONGITUDE>0</LONGITUDE>
  <SQUAWK>000</SQUAWK>
</MODESMESSAGE>
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: AirNav Development on July 04, 2009, 10:32:58 AM
We are happy to announce that RadarBox V3.0 Beta - Patch 1 is now fully compatible with SBS-1 output messages. We changed the way this is processed so all messages will be worked when they are received straight from the box. All formats mentioned above are support including AIR, ID and SEL messages.

We are passing a test exe to 2 beta testers and waiting for their feedback.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on July 04, 2009, 10:40:22 AM
We are happy to announce that RadarBox V3.0 Beta - Patch 1 is now fully compatible with SBS-1 output messages. We changed the way this is processed so all messages will be worked when they are received straight from the box. All formats mentioned above are support including AIR, ID and SEL messages.

That's very good news indeed.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: nortonbeak on July 04, 2009, 10:44:59 AM
Does that mean that RadarBox users will be able to supply data to the PP MLAT programme?
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: AirNav Development on July 04, 2009, 10:47:42 AM
The output from RadarBox is exactly like the output from SBS-1 from now on. So if you can do it with one application you can do with the other.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: AirNav Development on July 04, 2009, 10:54:11 AM
In addition we would like to thank DaveReid as we have based our development on the information he provided on this topic.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on July 04, 2009, 10:58:38 AM
Does that mean that RadarBox users will be able to supply data to the PP MLAT programme?

Unlikely.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on July 04, 2009, 01:29:32 PM
Does that mean that RadarBox users will be able to supply data to the PP MLAT programme?

Unlikely.

MLat doesn't do its calculations based on the socket output (since there's no useful information output in the socket data for non-positional aircraft by either RadarBox or SBS). 

So the answer is no, while socket output compatibility is desirable for lots of add-ons, on its own it won't facilitate MLat.

Having said that, I'd be surprised in AirNav aren't working on MLat solutions  :-)
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: AirNav Development on July 04, 2009, 01:37:56 PM
Who knows if we are... :-)
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: nortonbeak on July 04, 2009, 01:46:49 PM
Ah!  Now that will really be worth waiting for  :-)
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Fenris on July 04, 2009, 04:47:29 PM
Does that mean that RadarBox users will be able to supply data to the PP MLAT programme?

Unlikely.

MLat doesn't do its calculations based on the socket output (since there's no useful information output in the socket data for non-positional aircraft by either RadarBox or SBS). 

So the answer is no, while socket output compatibility is desirable for lots of add-ons, on its own it won't facilitate MLat.

OK Dave, so what does SBS send that is used by PP MLAT? I thought that it was simply the presence of a given aircraft near a given receiver being reported and then allowing for triangulation to obtain a best guess position?
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: DaveReid on July 04, 2009, 05:22:27 PM
OK Dave, so what does SBS send that is used by PP MLAT? I thought that it was simply the presence of a given aircraft near a given receiver being reported and then allowing for triangulation to obtain a best guess position?

MLat isn't triangulation, it's calculating position based on the time difference of arrival (TDOA) of the same signal from an aircraft being received by several different receivers.  These time differences are minute and can only be resolved if the application has access to the internal 20MHz clock/timer inside the SBS (presumably RadarBox has a similar one too).  In the case of the SBS, clever people than I have successfully decoded this data being sent from the box to the PC.  AFAIK, they haven't as yet with RadarBox :-)
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on July 04, 2009, 06:36:34 PM
The hack is a program that acts like a T-connector.  One end goes to the hardware box, one end goes to the Basestation program, and the other goes to the PlanePlotter program.  It is basically a shim that sits between the Basestation and the hardware.

There's a similar hack available for the Radarbox, that ouputs all the USB traffic on port 7070.  See http://mode-s.66ghz.com/radarbox-y-adapter.txt

Whether it could ever be used for MLAT is debatable.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: Fenris on July 04, 2009, 10:27:02 PM
OK Dave, so what does SBS send that is used by PP MLAT? I thought that it was simply the presence of a given aircraft near a given receiver being reported and then allowing for triangulation to obtain a best guess position?

MLat isn't triangulation, it's calculating position based on the time difference of arrival (TDOA) of the same signal from an aircraft being received by several different receivers.  These time differences are minute and can only be resolved if the application has access to the internal 20MHz clock/timer inside the SBS (presumably RadarBox has a similar one too).  In the case of the SBS, clever people than I have successfully decoded this data being sent from the box to the PC.  AFAIK, they haven't as yet with RadarBox :-)

Ah right, I didn't realise it was done like that, it's clearly capable of better accuracy than I thought it was.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: AirNav Development on July 05, 2009, 05:43:46 AM
We need 3 volunteers to test the new 30003 output on the current beta (before we release it to the public). It is a requirement that you know and often use SBS-1 addons. Please send us a PM if you are interested.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: tarbat on July 05, 2009, 04:34:13 PM
I'll have a file of a couple of hours, collected with sbssim, but I'm nowhere near Heathrow :(

Where do I find your SBSviewer program so I can test.
Title: Re: Post 30003 socket output format/emulation/compatibility
Post by: afo47 on July 09, 2009, 04:58:18 PM
which news ?
JLF