Abstract: A synthetic aperture radar in which echo returns received at sampling points over the length of the synthetic aperture are stored and correlated to form an image of the reflecting surface. The echo returns taken at sampling points over the first half of the synthetic aperture length are integrated to form a first synthetic monopulse beam, the echo returns taken from sampling points over the second half of the synthetic aperture length are integrated to form a second synthetic monopulse beam, and the first and second synthetic monopulse beams are linearly combined to provide synthetic monopulse sum and difference signals suitable for performing various beam sharpening functions in accordance with techniques in use with sum and difference signals provided by conventional monopulse antennas.

Abstract: A synthetic aperture radar antenna, which is mechanically scanned through the squint mode, is operated to a selected roll angle to optimize the alignment of the antenna beam axis or isogain line, and the line of constant doppler frequency or isodop line. The roll angle is selected as a function of the angular position of the antenna in azimuth and elevation.

Abstract: A pulse compression coherent radar for obtaining target information is described wherein a pulse compression waveform having a predetermined bandwidth is gated at a frequency greater than the predetermined bandwidth to form a sequence of spaced apart pulses which are transmitted towards a target. A sequence of target reflected pulses are received during predetermined time intervals. The target reflected pulses of the sequence are compressed and then filtered to extract predetermined frequency components of the compressed signal. Alternatively, the target reflected pulses of the sequence are first filtered to extract predetermined frequency components and then compressed. In either embodiment, the output signal contains target doppler frequency and phase, range, and amplitude signature information. The gated pulse compression waveform may be for example a chirp or linear FM signal, phase coded signal, or pseudo noise coded signal.