Abstract: A radar system determines the range and velocity of a target, such as an atmospheric structure. The radar system transfers a first series of pulses and a second series of pulses. The first series of pulses and the second series of pulses have orthogonal polarizations. The first series of pulses and the second series of pulses have a same pulse repetition time. The first series of pulses and the second series of pulses are offset by a time amount. The target reflects energy from the first series of pulses to generate a first series of echoes and reflects energy from the second series of pulses to generate a second series of echoes. The radar system processes the first series of echoes and the second series of echoes to determine the range and velocity of the target.

Abstract: An on-vehicle radar system capable of detecting a range error from range data based on an echo from a target (6). Range error is detected when amplitudes of beat frequency components in two adjacent range gates are substantially equal. The system includes a transmitting unit (1, 2, 4, 5) for radiating a modulated wave having frequency increasing and decreasing repetitively after pulse modulation, a receiving unit (8, 9, 10, 11, 12) for receiving the echo, and an arithmetic unit (13) for detecting a range error ascribable to aberration of modulation band width due to frequency increase and decrease of transmission wave (W1) by comparing a range corresponding to the range gate with that determined from a frequency difference between transmission wave and echo. The arithmetic unit (13) detects the range error on the basis of frequency difference components having substantially same amplitudes in adjacent range gates.

Abstract: A design methodology for jointly optimizing the transmit waveform and receiver filter for multiple target identification is presented in presence of transmit signal dependent clutter like interference and noise. The methodology is applied and illustrated for various multiple ‘target ID’ problems in presence of transmit signal dependent clutter like interference and noise. The resulting correct target classification is significantly better than that achieved by a conventional chirp or any other transmit waveform. Unlike the classical radar case, the choice of transmit pulse shape can be critically important for the detection of extended targets in presence of additive channel noise and signal-dependent clutter.

Abstract: Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.