ADS-B “IN” at Ballina?
Ground radar is a combination of ADSB and primary, so tower controllers can see both (usually). I understand that the TCU's are generally primary and secondary only, but I could well be wrong about that.
I had a controller say recently “I can’t see you on ADSB because I can see you on mode C” which I found interesting.
Would be good to hear from an ATC’er as to what actually appears on the screen.
Would be good to hear from an ATC’er as to what actually appears on the screen.
I built one of the Stratux ones. Amazing thing is how many (even high level RPT aircraft) you can spot visually, with the aid of the output of the unit displayed on the EFB screen. None of those high level aircraft is a collision risk - very ‘high’ while us nobodies are very ‘low’ - but it does demonstrate that the unit picks up and provides pretty accurate information about aircraft putting out Mode C data.
But the ‘blindspot’ is that it requires ‘something’ to be interrogating the other aircraft’s transponder….
But the ‘blindspot’ is that it requires ‘something’ to be interrogating the other aircraft’s transponder….
This may be better explanation: https://www.icao.int/meetings/amc/ma...sitf4/sp01.pdf
Last edited by MechEngr; 5th Jun 2022 at 23:34.
Thanks ME. If ADS-B out equipped aircraft are ‘automatically’ transmitting position/alt through their Mode C transponder every second or so, I stand corrected in relation to those aircraft. Doesn’t seem to help with aircraft wth Mode C transponders but not ADS-B out, though. Presumably they have to be interrogated by ‘something’, first?
In ADS-B only coverage we see a four bladed "propeller" symbol and the "b" disappears. For TCU they still see a circle symbol regardless of whether it's SSR or ADS-B.
We can toggle the display to show what you're squawking but SSR takes priority if both are being received, i.e. we can't see your ADS-B code while you're in SSR coverage.
Thanks LP, most helpful.
One more thing :-) are there changes in colour on the screen icons if the GPS is certified to TSO199 versus 146 / approved but not certified?
One more thing :-) are there changes in colour on the screen icons if the GPS is certified to TSO199 versus 146 / approved but not certified?
Most TCU do not receive adsb. They need an extra processor to convert the adsb returns into a fake radar return. This is available in sydney, melbourne and hobart.