B. Butler (Oregonian)
(Top Gun)
12/19/17 04:49 PM
Re: Tracon Radar Snafu?


OK...I must have been in "coast".
Was the system predicting my position and not reporting it?
Pretty sure he said coast...

Yes. Thats what happens. The underlying radar gives real-time position, updated every 10 seconds (center radar) or 4 in terminal, but the computer that associates a data block with your transponder simultaneously predicts your next position based on track and speed history and if it doesn't see a radar target, it goes there anyway and announces "CST".

The computer is looking for your transponder in a fairly small circle of possibility and it is very easy to make a sharp turn, to join a course, for instance and sling the data block off on a tangent.

The system isnt hopelessly stupid though, and on each update it expands the circle of possibility, but there is an internal plausibility check it does, so you can CST for a while. It is precisely why every controller is supposedly taught to control the target, not THE FRAPPIN DATABLOCK!

Ahem...sorry.. I think the above fits your case.

Contact Us AVSIG

Powered by UBB.threads™ 6.5.5

Logout   Main Index    AVSIG Aviation Forum