PlaneFinder Radar Receiver in far remote area?

[PE2G]

Hello,

This probably is a stupid question but here goes: Would the PFR Receiver still show aircraft in far remote areas without SSR Mode S or any other SSR interrogation by ground stations?

In other words: Does the receiver listen to Mode S ELS / EHS replies from aircraft or to ADS-B (Mode S ES / 1090 ES)?

Thank you for enlightening me.

Cheers,
Frits

 

[Lee Armstrong]

This is more an ADS-B receiver question in general as none are allowed to interrogate the aircraft. It is also down a little to the decoder but here is how we work.

If we can check the CRC of a Mode-S/ADS-B packet we deem the aircraft valid. Any further replies from an aircraft are then listened to. ADS-B is squitted and so are a lot of Mode-S values. The EHS stuff needs a ground station to request it. So...if it is asked for it, we listen to it!

 

[PE2G]

Thank you Lee, for the info. Am I correct to understand that only ADS-B "squitters" contain GPS position information, or can GPS positions also be present in replies to Mode S ELS/EHS interrogation by ground radar?

Thank you again,
Frits

 

[Lee Armstrong]

Correct, DF-17 packets are the only ones that contain the lat/lon (well one half anyway!). You need to packets to get an actual position.