[time-nuts] Aircraft ping timing

David I. Emery die at dieconsulting.com
Thu Mar 20 02:48:56 EDT 2014

On Wed, Mar 19, 2014 at 09:28:38PM -0700, nuts wrote:
> A lot of these satellites have "footprints" for each antenna. I don't
> know if the footprints are narrow enough to track a plane.

	I do believe there is an time offset for each aircraft sent on
the forward control channel from the ground (which is shared with many
aircraft) that allows a particular  aircraft to transmit a frame in the
center of its allocated slot.   IIRC the ground measures the error and
sends a correction to the plane which allows the plane's transceiver to
compute just when - relative to the system frame timing derived from the
received forward control channel from the satellite  - it should
transmit the reverse control channel burst.

  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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