The doppler radar set is a self contained airborne radar system which provides continuous readouts of aircraft groundspeed and drift angles of up to 90 degrees to the left or right. This information with GHARS generated signals to provided conditioned signals.

The doppler antenna is located in the bottom of the aircraft near the front, labelled 13 in the accompaning diagram.

GHARS provides heading, pitch and roll to orient measured velocity data for the hover indicators as well as conditioned signals for the ASE, GHARS and ASN-123 systems.