VDL2 Ground Stations

[morfis]

.... How likely is it to intercept stuff from the aircraft near a major city?

I live between two major airports...about 15 miles to each. One has both SITA and ARINC uplinks which I receive from home (I've not seen any uplinks from the other but can see no sensible reason for it to need uplink capability anyway).
I receive downlinks from aircraft within a 150 mile radius when using my small 2m colinear.

 

[ATCTech]

If you were receiving the G/S transmissions in some messages there should be a Lat/Long and an 'Airport coverage' text portion as part of the uplink which would identify the locations. (Depending on what software you're using.)

From dumpvdl2 for example:

[2018-10-20 17:39:25 GMT] [136.975] [-31.2/-46.8 dBFS] [15.6 dB] [-0.5 ppm]
1024FA (Ground station, On ground) -> C0550C (Aircraft): Response
AVLC: type: U (XID) P/F: 1
XID: Handoff Response
Public params:
Parameter set ID: 8885:1993
Procedure classes: 00 01
HDLC options: 20 84 80
N1-downlink: 07 d8
N1-uplink: 07 d8
VDL params:
Parameter set ID: V
Connection management: 01
XID sequencing: 06
AVLC specific options: 20
Airport coverage: CYYZ
ATN router NETs: 00 00 00 00 00 00 "......"
System mask: fc 02 00 00
Ground station location: 43.7N 79.6W

A squitter message from the G/S (always addressed to "FFFFFF" will contain it for sure.

Cheers!

 

[EricCottrell]

Hello,

I found some aircraft indicating they are on the ground when talking to distant ground stations. It turns out they were airborne. I noticed the LSD (lower 4 bits) of the address is a hex A for ARINC ground stations, and a hex 7, 8, or 9 for SITA ground stations.

10108A
10145A
10147A KALB ARINC
1014CA
1014FA
10153A
10158A
10159A
10184A
1018AA
1018DA
10190A
10201A
10254A
10258A
10259A
1029FA
102C0A
102C1A
102C3A
10308A
10309A
10347A
10348A
10349A KALB ARINC
1034DA KBOS ARINC
10352A
10405A
10412A KALB ARINC
10456A
1045AA
1049AA
104C3A
104CBA
104CCA
104CDA
10502A
10503A KBOS ARINC
10508A
10516A
10547A
10547A
1054BA KBWI ARINC
10552A
208F37
211197
213E77 KBOS SITA
213E78 KBOS SITA
2154D7
2154D8
215D37
22DE57
22DE58
2441D7
251977
251978
251979
261C37
261C38
282197
282198
285897
2A1457
2CB717
2CD597

73 Eric

 

[EricCottrell]

Hello,

I forgot to mention I heard a second SITA station at Logan. It does not broadcast it's info frame very often. Most of the traffic is handed by 213E77.

213E78 (Ground station, On ground) -> FFFFFF (Aircraft): Command
AVLC: type: U (XID) P/F: 0
XID: Ground Station Information Frame
Public params:
Parameter set ID: 8885:1993
Procedure classes: 00 01
HDLC options: 20 a4 88
VDL params:
Parameter set ID: V
AVLC specific options: 20
Timer T4: 00 02
Airport coverage: KBOS
ATN router NETs: 00 00 00 00 00 00 "......"
System mask: 94 00 00 00
Ground station location: 42.4N 71.0W

73 Eric

 

[ATCTech]

Hi Eric,

It's been determined that G/S idents starting with a 1 are ARINC while those starting with a 2 are SITA, at least in North America and Europe. There are other VDL operators in other parts of the world, Italy, Asia and Japan for sure. We haven't seen any G/S data from these locations posted to date....

Cheers!

Bob

 

[kma371]

Listened a bit longer and got an ID

10507A Ground Station
KSFO San Francisco
37 36'N 122 24'W

 

[ATCTech]

About how many NM are you from SFO? If I remember correctly from your previous posts on other reception topics you've got loads of elevation working for you there. I'm about 18NM from CYYZ Toronto and see the 3 G/S transmitters and all 5 legacy ACARS transmitters I'd say about 90% of the time, depending on noise levels and whether they're on the A or B sites. I know first-hand from working there with ARINC and SITA as customers that they have 2 operational installations for each frequency in different locations on the airport. My coverage to YYZ is over relatively flat ground but with a major highway and the construction of large buildings it attracts, so my line of sight is mathematical but not literal.

Cheers!

Bob

 

[AirScan]

Hi Eric,

Thanks for posting the info. from the Boston area. As our coverage areas overlap it helps me up in Ottawa determine the approximate location of some the GS's I'm seeing up here. So far after a few weeks of monitoring vdl2 I've seen 49 ARINC and 20 SITA GS's.

15 of those received in Ottawa, you are not getting in Boston ...

1015BA
1019FA
1024FA - CYYZ
10307A - CYOW
1030AA - CYYZ
1031DA
1039BA
10403A
10421A
1044EA
104C3A
104CDA
104D2A
11512A
2CE757 - CYYZ

And the 11 stations you are getting in Boston, but I'm not in Ottawa ...

10108A
1018AA
1029FA
10347A
104CCA
10516A
1054BA - KBWI
10552A
215D37
22DE58
251977

Plotting range rings at 200nm/400nm narrow's down the general area of the missing ground stations.

Great Circle Mapper

Do you monitor 136.650 at all, wondering if you are getting much traffic on that frequency in Boston ?

From what I have seen it looks like ARINC uses 11xxxx to ID 136.650 stations (10xxxx for 136.975).

According to the FCC database 136.650 is active at the following airports (from East to West) -

JFK, LGA, EWR, PHL, DTW, BNA, MDW, ORD, STL, PHX, LAS, SAN, LAX, OAK.

https://fjallfoss.fcc.gov/General_Menu_Reports/engineering_search.cfm?accessible=NO

AS

 

[DaveNF2G]

If you were receiving the G/S transmissions in some messages there should be a Lat/Long and an 'Airport coverage' text portion as part of the uplink which would identify the locations. (Depending on what software you're using.)

From dumpvdl2 for example:


Cheers!

MultiPSK does not decode any of that location info from air-to-ground messages. It looks like something that is specific to the Linux program you are using.

 

[morfis]

MultiPSK does not decode any of that location info from air-to-ground messages. It looks like something that is specific to the Linux program you are using.

That message was ground to air not air to ground.

After seaching through a weeks worth of logs of all three frequencies (using dumpvdl2 and three multipsk instances) here I can find no air to ground message that has that kind of location info in it.

 

[EricCottrell]

Hello,

Here are the VDL2 stations I found in New England via a FCC license search.

ARINC
WBD8	BANGOR INTERNATIONAL AIRPORT	44-48-29.4 N, 068-49-00.4 W
WBE7	TWEED NEW HAVEN AIRPORT		41-15-50.3 N, 072-53-13.4 W
WDR4	Manchester Airport		42-56-00.3 N, 071-26-16.2 W
WPSQ723	Portland Intl Jetport		43-38-50.3 N, 070-18-37.8 W
WPSR810	Site B: Logan Intl Airport		42-21-51.3 N, 071-00-19.1 W
WQFA517 Burlington International Airport	44-28-24.5 N, 073-08-46.8 W
WQGS282 Laurence G. Hanscom Field	   42-27-47.0 N, 071-17-25.0 W
WQND696 Nantucket Memorial Airport	41-15-31.7 N, 070-03-52.3 W
WQY6	Theodore Francis Green State Airport	41-43-30.6 N, 071-25-17.5 W
WRA5	BRADLEY INTERNATIONAL AIRPORT	  41-56-20.3 N, 072-40-58.3 W
WRA9	LOGAN INTERNATIONAL AIRPORT-VSAT	42-22-24.6 N, 071-01-20.7 W
WSE6	DAIGLE HILL AROOSTOKK COMM SITE	47-11-57.6 N, 068-27-30.5 W

SITA
WAS42 	BOSTON LOGAN INTERNATIONAL AIRPORT	42-22-11.0 N, 071-01-10.6 W
WQJA684 Genl Edward Lawrence Logan Intl Airport 42-21-44.0 N, 071-01-29.0 W
WQJA687 Nantucket Memorial Airport	41-15-31.9 N, 070-03-51.7 W
WSH74	BRADLEY INTL AIRPORT	41-56-17.5 N, 072-40-34.0 W
WVA6	THEODORE FRANCIS GREEN STATE AIRPORT 41-43-32.7 N, 071-26-06.4 W

73 Eric

 

[kma371]

About how many NM are you from SFO? If I remember correctly from your previous posts on other reception topics you've got loads of elevation working for you there. I'm about 18NM from CYYZ Toronto and see the 3 G/S transmitters and all 5 legacy ACARS transmitters I'd say about 90% of the time, depending on noise levels and whether they're on the A or B sites. I know first-hand from working there with ARINC and SITA as customers that they have 2 operational installations for each frequency in different locations on the airport. My coverage to YYZ is over relatively flat ground but with a major highway and the construction of large buildings it attracts, so my line of sight is mathematical but not literal.

Cheers!

Bob

At the time, I was about 5 NM from SFO mobile, with a very minimal antenna setup. I have access to a high level site, but it is approx. 100 miles east of SFO. I'll try and get closer on my next days off and see if I can pick up the stations from SFO and OAK.

 

[ATCTech]

Eric, are these all 136.975 MHz?

Cheers!

Bob

 

[AirScan]

Hi Dave,

I sat at my local airport (KALB) for several hours on Monday and received no squitters on any ACARS frequency. There were no acknowledgments on VDL2 for data sent from aircraft on the ground, either. However, I did infer the VDL2 hex codes for KALB based on where the landed aircraft's messages were addressed.

10147A [KALB Albany International 42°44'N 073°49'W] [Albany, NY]
10349A [KALB Albany International 42°44'N 073°49'W] [Albany, NY]
10412A [KALB Albany International 42°44'N 073°49'W] [Albany, NY]

I just came across some recent logs from the New York City area. The location is not close enough to receive any uplinks to confirm GS's ID's, but close enough to get aircraft within a minute or so after they are airborne.

Looking at JFK departures I notice a lot of them are transmitting to GS 10147A immediately after takeoff. Which leads me to believe that this is a JFK site, not ALB (as it would be well out of range).

AS

 

[DaveNF2G]

Looking at JFK departures I notice a lot of them are transmitting to GS 10147A immediately after takeoff. Which leads me to believe that this is a JFK site, not ALB (as it would be well out of range).

AS

I concur. I have also seen from other postings in a related thread that there is no VDL2 ground station licensed at Albany, so JFK is a much better candidate.

 

[AirScan]

I have also seen from other postings in a related thread that there is no VDL2 ground station licensed at Albany

I just checked the FCC database. It shows a station WRD2 in Albany "active" 136.975 with an emission designator 14K0G1D.

ULS License - Aeronautical and Fixed License - WRD2 - Aviation Spectrum Resources Inc - Locations Summary

AS

 

[morfis]

The ground stations apparently being addressed by aircraft can be qite strange. Watching some aircraft on approach to EGCC I saw that they were addressing 11983A when down at 5000'. That might lead one to suppose that adress is for a VDL2 terminal at EGCC but it is in fact at EGLL. It wasn't until they were down at 1000' that the aircraft swapped to addrssing 1099CA (which is a terminal at EGCC).
There is no way that the aircraft were communicating directly to the terminal at EGLL at that height/distance.

Quite fascinating seeing you combining your knowledge and your observations. No nice lists of VDL2 terminals publicly available here....and aviation frequency licncing is not in the public domain. In the early days of hobby ACARS monitoring I enjoyed chatting to Ed Flynn as it seemed no-one over here was remotely interested!

 

[DaveNF2G]

Here is just part of my logging of 136.650 MHz over the past weekend from the vicinity of Albany, NY:

10145A
ACA90 CYYZ-SBGR
CES297 ZSPD-KJFK
SIA51 KIAH-EGCC-WSSS
UAL386 KDEN-KBOS

10147A
AAL300 KJFK-KLAX
CES297 ZSPD-KJFK
CPA84 KJFK-CYYZ-PANC-VHHH
CSN399 ZGGG-KJFK
ICE644 KIAD-TIFF
N417LX to CZYZ

1014FA
AAL2702 KMIA-CYUL

10153A
CCA989 ZBAA-KJFK
UAL931 KORD-EGLL

10158A
UAE212 KIAH-OMDB

10158E
VIR8E KLAX-EGLL

10184A
CCA989 ZBAA-KJFK

10190A
SWA799 KSTL-KBOS

1024FA
ASA172 KPDX-KBOS

10257A
SWA1264 KLGA-KMDW

10258A
AAL1044 KLAX-KBDL
CCA989 ZBAA-KJFK
ENV3365 KORD-KPVD
SKW3640 KDTW-KPWM

10259A
DAL868 KMSP-KBOS
SKW3725 KDTW-KHPN

102C0A
N417LX to CZYZ

10309A
AAL1044 KLAX-KBDL
NKS641 KBOS-KLAS

10348A
AAL304 KBOS-KORD
AWI3849 KALB-KIAD
CES297 ZSPD-KJFK
CSN399 ZGGG-KJFK

1034DA
AAL304 KBOS-KORD
UAL670 KSEA-KORD-KBOS

10405A
UAL2275 KEWR-KSAN
UAL2327 KEWR-KLAS

10456A
SKW3045 KORD-KHPN
SKW3725 KDTW-KHPN

104C3A
RCH5564 KADW-EFRO

10503A
ASA24 KSEA-KBOS
NKS641 KBOS-KLAS
SWA799 KSTL-KBOS
UAL386 KDEN-KBOS

10508A
EDV5390 KJFK-KSYR

10547A
UAL1013 KSFO-KDEN-KLGA

208F37
SWG307 SNU-CYUL

211197
CHH7915 ZUUU-KJFK
DAL514 KBDL-KDTW
DAL1562 KDTW-KBDL
JBU334 KSFO-KBOS
JBU688 KLAX-KBOS
PAL127 KJFK-CYVR-RPLL
SWG689 MUVR-CYUL
TSA860 CYUL-MKJS

213E78
JBU688 KLAX-KBOS

2154D8
JBU516 KSFO-KJFK

220C37
SWG689 MUVR-CYUL

2441D7
QTR708 KIAD-OTHH

251978
CLX454 KJFK-ELLX
DAL428 KJFK-KLAX
DAL1562 KDTW-KBDL

251979
JBU

261C37
DAL1562 KDTW-KBDL
JBU97 KJFK-KDEN
TSA860 CYUL-MKJS

261C38
TSA860 CYUL-MKJS

2A1457
CAL11 KJFK-RCTP
SWG689 MUVR-CYUL

This might help to nail a few GS identifications down. At least three of them are in Canada.

 

[AirScan]

Dave,

Here is just part of my logging of 136.650 MHz over the past weekend from the vicinity of Albany, NY

Thanks for that report but are you sure those flights are on 136.650 ? I looked over my logs from this weekend too and and did not catch any flights on 136.650. ALB is 174nm from YOW so our coverage areas overlap quite a bit.

Great Circle Mapper

My reception range to the south is pretty good, I routinely get position reports from aircraft overhead Albany. So I would expect to see at least some of those on 136.650. The thing is I am getting a lot of those flights to the same GS's you show but my software (dumpvdl2) says they are all on 136.975.

I have received the odd message on 136.650, all to GS 11512A (probably DTW), so I think it's accurate on my end. Could it be that your system/software is indicating the wrong frequency somehow ? Or was 136.650 a typo and you meant 136.975 ?

AS

 

[AirScan]

morfis,

The ground stations apparently being addressed by aircraft can be qite strange.

Same thing over here, I've seen approaching traffic logged on to the local GS switch to further away stations as they get closer to the airport, then back and forth between even further ones until finally getting back to the local one before landing.

Only have an ARINC GS here on 136.975 so SITA aircraft get confused as they get closer to the airport and try to connect with a bunch of further away SITA stations before finally giving up on VDL2 and switching to the SITA POA (Plain Old ACARS) frequency 131.725.

I've also seen a few "transgender" aircraft that can switch from SITA to ARINC as they get closer to the airport.

AS