Abstract: A radar system mounted on a satellite is scanned to provide surveillance of large areas such as the oceans. The transmitter oscillator generates bursts in the frequency range from about 20-250 megacycles. A receiver detects signals reflected from objects in the target area. The receiver enhances the value of recurrent components of selected time interval portions of the received signals. In one embodiment the transmitter bursts are modulated in accordance with a predetermined modulation pattern. The system determines to what extent it corresponds to the predetermined modulation pattern and then enhances the value of the recurrent components of the received signals. The enhancement is of those recurrent components having relative phases which change by substantially uniform increments.

Abstract: A method and apparatus for removing the effects of radar platform movement and for otherwise processing doppler radar signals in a moving target indicator doppler radar in which targets in the main beam having reflective characteristics sufficient to override side lobe attenuation are tracked relative to the side lobes and the residual doppler frequency for such targets resulting from side lobe detection calculated. Based on this calculation, the appropriate ones of a bank of doppler filters are inhibited at the appropriate range bin to prevent a false target indication without inhibiting the display of moving targets in the main beam at the same range but having different doppler frequencies.

Abstract: An airborne early warning moving target indicator radar in which targets in the main beam having reflective characteristics sufficient to override side lobe attenuation are tracked relative to the side lobes and the residual doppler frequency for such targets resulting from side lobe detection calculated. Based on this calculation, the appropriate ones of a bank of doppler filters are inhibited at the appropriate range bin to prevent a false target indication without inhibiting the display of moving targets in the main beam at the same range but having different doppler frequencies. In addition to side lobe blanking, an automatic gain control circuit is provided in which the interpulse period is divided into a large number of equal time intervals on the order of 0.4 microseconds each to thereby separate the return signal from each radar pulse into a large number of range bins.

Abstract: An automatic gain control circuit including a wide band digitally controlled amplifier particularly adapted for use with recurring signals. Each of the recurring signals is divided into a large number of discrete time intervals and the gain of the amplifier may be adjusted for each time interval independently of the signal in any other of the time intervals. Transients due to gain modification may be superimposed.