Ground-to-air imaging radar for RCS measurement

ISAR images and RCS data of a Mooney 231 aircraft, obtained using an advanced portable instrumentation radar system, are presented. The Mooney 231 flew in a controlled path in both clockwise and counterclockwise orbits, and successively with gear down, flaps in the take-off position and with the speed brakes up. The radar used operates in the 7-11 GHz region, has a maximum continuous bandwidth of 4 GHz, has programmable waveforms, uses a transmitter with 200 W peak power and can be operated in a search mode with open-loop manual alignment or in an acquisition mode with a closed-loop angle and range track. The antenna configuration consists of a three-dish system, utilizing a single-polarity transmit antenna, a track receive antenna-monopulse comparator, and a dual-polarity receive antenna. The data indicate that this system is a useful tool for RCS signature diagnostics of aircraft in flight.>