Patent ID: 6677900
Filing Date: 2004-01-13
Classification: G01S

Abstract:
A receiver for detecting mobile objects, using digital telebroadcast terrestrial radio transmissions, made by transmitters that commonly operate based on a plurality of fixed frequency carriers, afforded a symbol-based digital modulation, processed by carrier-wise orthogonal frequency multiplexing, the receiver comprising:radioelectric reception means for picking up signals backscattered by objects under effect of said radio transmitters; processing means for performing a discrimination of the objects according to distance/Doppler bins; and auxiliary means for acquiring a synchronization reference with respect to the transmitters, to clamp the distance/Doppler bins in time, wherein the auxiliary means comprises means for receiving and demodulating the direct radio telebroadcast signal received from at least one of the transmitters, to determine instants of synchronization and symbols of the at least one of the transmitters; and wherein the processing means comprises: Doppler distribution means for apportioning signals received according to a plurality of Doppler pathways, while affording signals in each pathway a frequency shift associated with a rank of the respective Doppler pathway, distance compression means for forming a sum for all the carriers of correlations, in homologous forms, of an output of each Doppler pathway with symbols available at an output of the auxiliary means, thereby yielding samples arranged in the distance/Doppler bins, means for coherent Doppler integration over a chosen time, thereby yielding integrated distance/Doppler bins, and means for postprocessing with tracking, to contrast echoes obtained in the integrated distance/Doppler bins, to obtain radar plots containing position/velocity information on one or more of the objects.