Radar apparatus
AssigneeHollandse Signaalapparaten B.V.
InventorBernard Gellekink
Life of this patent
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Abstract
A radar apparatus having a phased array antenna with a large number of transmit and receive modules, a control unit and a video processor. The control unit generates a number of pulse bursts per azimuth-elevation direction, all of which shows slight carrier frequency differences. The video processor determines a doppler spectrum and compared successive spectra for each pulse burst. As a result of the frequency differences, clutter does not show much of a shift while targets which are subject to fold-back in the frequency domain will show considerable shift. A threshold based on a mean spectrum therefore enables detection.
Claims9
Radar apparatus for the detection of high-speed targets, comprising antenna means, transmitter means for the generation, per antenna direction, of at least M bursts of at least N transmitter pulses, with M=2, 3, . . . , N=2, 3, . . . , receiver means for the reception, per transmitter pulse, of a radar echo signal determined per range quant, and a video processor connected to the receiver means, comprising an N-point doppler filterbank for the processing, per burst and per range quant, of the radar echo signals into an N-bin doppler spectrum and a threshold circuit, provided, for each range quant, with N threshold values for the generation of an alarm when crossing of at least one threshold for at least one range quant occurs, characterized in that the threshold circuit comprises a threshold generator for the generation, per range quant, of N threshold values on the basis of P doppler spectra obtained from P successive bursts, with P=2, . . . , M.
Dependencies are inferred from the claim text.