Doppler radar analysis techniques - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 429

Figure A.3. FAST: scanning technique used by the airborne radar ELDORA and illustration
of the pseudo dual-Doppler synthesis of the wind field for beams that trace out cones alter-
nately in the fore and aft directions. (Top) Scanning illustrated at a fixed time; the antennas and
radome rotate as a unit about an axis parallel to the longitudinal axis of the aircraft. The fore
and aft angles are

and the angle measured in the clockwise direction about the longitudinal

r . (Bottom) Idealized example of beam intersections in a flight by the
convective storm (from Hildebrand et al., 1996).

axis of the aircraft is