Author Topic: Transmitting 2 ADS-B Signels  (Read 2185 times)

Richard

Transmitting 2 ADS-B Signels
« on: August 20, 2015, 11:14:54 am »
Hi

Just going a step further into fitting PilotAware into an Aircraft. If the Aircraft has ADS-B connected and active via the transponder, then using PilotAware the Aircraft would be transmitting 2 ADS-B singles.

OK Air Traffic will only receive the signal carried by the transponder ADS-B out, but if you spot that aircraft on your sky demon, Will you see two Aircraft together?

It may be advisable to disconnect the PilotAware ADS-B transmission if you are using the Aircraft Transponder to transmit your ADS-B signal

Have I got this correct?

Richard.
Europa XS

Admin

Re: Transmitting 2 ADS-B Signels
« Reply #1 on: August 20, 2015, 11:35:42 am »
Hi

Just going a step further into fitting PilotAware into an Aircraft. If the Aircraft has ADS-B connected and active via the transponder, then using PilotAware the Aircraft would be transmitting 2 ADS-B singles.

OK Air Traffic will only receive the signal carried by the transponder ADS-B out, but if you spot that aircraft on your sky demon, Will you see two Aircraft together?

It may be advisable to disconnect the PilotAware ADS-B transmission if you are using the Aircraft Transponder to transmit your ADS-B signal

Have I got this correct?

Hi Richard,
Luckily (for once) I have already thought this through.
PilotAware will indeed receive 2 signals, ADS-B & P3I.
Internally PilotAware compares the ICAO code for both signals, in other words it has something like this

(A) denotes ADS-B, (P) denotes P3I

(A) ICAO=123456, position=....
(A) ICAO=ababab, position=....
(A) ICAO=401010, position=....
(P) ICAO=deed00, position=....
(P) ICAO=123456, position=....    // Filtered out before forwarding

So it detects multiple entries for the ICAO 123456,
in this case it only sends the ADS-B values on to the navigaion display tool, suppressing the P3I values.

This is why in CollisionAware there is an entry for ICAO, this MUST be the same as the entry for the ADS-B transponder, otherwise the filtering does not work and as you correctly point out, you will display 2 aircraft at the same location.

Thx
Lee
« Last Edit: August 20, 2015, 11:38:12 am by Admin »

Richard

Re: Transmitting 2 ADS-B Signels
« Reply #2 on: August 20, 2015, 12:20:36 pm »
Lee,
   Thank you for the reply. You are on the ball with this.
It's nice to know what's happening inside the little box

Richard
Richard.
Europa XS