foxbravo03
Posts: 35
Joined: Mon Mar 08, 2004 5:44 am

ADS/CPDLC

Sat Mar 27, 2004 4:50 am

Hello,
I know CPDLC=Controller Pilot Data Link Communication,but can someone explain what ADS stands for,and the difference between the two?
Regards,
foxbravo03.
 
Contact_tower
Posts: 534
Joined: Mon Sep 17, 2001 4:05 am

RE: ADS/CPDLC

Sat Mar 27, 2004 8:46 am

ADS = Automatic Dependent Surveilance. A joint term for the systems where a transmitter in an aircraft transmits it's GPS position to a com sattelite (or ground station), allowing "radar-like" surveilance all over the globe. CPDLC is a part of some ADS systems, but not all. CPDLC have been seen as a replacement for VHF/HF radio coms over oceans etc.
 
buckfifty
Posts: 1278
Joined: Tue Oct 16, 2001 4:05 pm

RE: ADS/CPDLC

Sat Mar 27, 2004 12:56 pm

In Sweden, ADS will replace SSR as the primary means of tracking aircraft, especially in the Northern part of the country. Quite a useful tool that is.
 
Contact_tower
Posts: 534
Joined: Mon Sep 17, 2001 4:05 am

RE: ADS/CPDLC

Sat Mar 27, 2004 2:54 pm

"In Sweden, ADS will replace SSR as the primary means of tracking aircraft, especially in the Northern part of the country. Quite a useful tool that is"

Well......not quite. It will give surveilance to a part of the country that has no radar coverage below about FL100. (At best)

And I agree, it's a good tool, but the issue of getting ADS "transponders" into ALL aircraft is still a major hurdle. To us controllers ADS is no good for seperation if not everyone has it.
 
foxbravo03
Posts: 35
Joined: Mon Mar 08, 2004 5:44 am

RE: ADS/CPDLC

Sat Mar 27, 2004 5:09 pm

Hello,
I've noticed that the ADS/CPDLC system seems to be used more by the airlines than General Aviation traffic.The GA guys continue to rely on voice reports for their position reporting on HF.Is there any reason for this?
Thank you for your replies so far.
Regards,
foxbravo03.
 
backfire
Posts: 3467
Joined: Fri Oct 06, 2006 8:01 am

RE: ADS/CPDLC

Sun Mar 28, 2004 8:23 am

Sounds like there's some confusion here.

ADS and CPDLC are both datalink-based technologies but otherwise have nothing to do with each other.

ADS is a surveillance technique by which an aircraft transmits regular position reports via satellite to ground controllers or even to surrounding aircraft.

CPDLC is a communications technique whereby routine air traffic control instructions are transmitted between display screens (rather like e-mail) instead of over congested VHF frequencies.
 
ba299
Posts: 182
Joined: Wed Jun 04, 2003 9:18 pm

RE: ADS/CPDLC

Mon Mar 29, 2004 3:45 am

We just started the ops use (after a long period of test) of the ADS/CPDLC and I think it's great. I can't understand the old pilots that don't like it.
 
PhilSquares
Posts: 3371
Joined: Sun Mar 28, 2004 6:06 pm

RE: ADS/CPDLC

Tue Mar 30, 2004 1:51 am

Just a comment on Ba229's statement about "old pilots that don't like it". Being an "old pilot" feel I can comment. I don't think it is an issue of not liking it, or even not willing to change, I think it, atleast for me, is an issue of what the trade off is.

The nice thing about VHF communications is you have a "party line". You can hear other transmissions, you can build a mental picture of where everyone else is around you. It helps situational awareness.

I am all for decreasing pilot workload. In this day and age, it's ridiculous to go across the Pacific or other parts of the world and have to rely on HF as your primary form of communication.

I have used FANS for a number of years and love it, I just wish there was some way keep the information coming into the cockpit to keep us situationally aware of the traffic in your area.
Fly fast, live slow
 
ba299
Posts: 182
Joined: Wed Jun 04, 2003 9:18 pm

RE: ADS/CPDLC

Wed Mar 31, 2004 8:37 pm

I don't think that are situational awareness. We already don't heard the position report on HF on the north Atlantic so for me it's a no reason.
ADS can be safer that talk on the HF.
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: ADS/CPDLC

Wed Mar 31, 2004 9:22 pm

Just one point. The aircraft will transmit to the ground and each other directly, in a TCP/IP-ish kind of wireless network. No satellites involved once the position has been determined.  Smile

I do hope that the datalink comms will enable you to see all the traffic in the surroundinds, with messages concerning your own flight highligted. Theoretically, you could even make it user configurable. "I want to see ATC comms for all aircraft within altitude block xxx-yyy and within an n mile radius". Wouldn't that be neat?

Of course, once you have the display you already know as much about the situation as ATC without listening in on the comms...

Cheers,
Fred

I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
PhilSquares
Posts: 3371
Joined: Sun Mar 28, 2004 6:06 pm

RE: ADS/CPDLC

Thu Apr 01, 2004 12:28 am

Actually, the CPDLC used in the FANS system does use satellites to rely the data link to a ground station. If I remember correctly, it's the INMARSAT system that is used.

I beg to differ again with BA229. It was very informative listening to Shanwick or Gander while people got their oceanic clearance. You knew who was where in the track system and what altitudes people got. Now, it's just the non data link a/c that get the clearances over VHF. In addition, if the FAA has their way, they would like to use CDPLC in the terminal area.

Several years ago, I did some volunteer work at the NLR to look at the applicability of CPDLC. IFALPA and U.S. ALPA funded the study. The results were very interesting. They were given to the FAA and ICAO. Sadly, it looks as if the FAA didn't read the study.

Again, just my opinion as an "old pilot".
Fly fast, live slow
 
User avatar
RobK
Posts: 3212
Joined: Mon Sep 06, 2004 1:43 pm

RE: ADS/CPDLC

Tue May 10, 2011 12:30 pm

Sorry to bump a 7 year old thread  Wow! but this seemed like an appropriate place to post my question as it's related. So we know what CPDLC and ADS comms are, but what is FMC and how does position reporting in OCAs work with that?

 

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