Patent ID: 8144049
Filing Date: 2012-03-27
Classification: G01S,H01Q

Abstract:
1. A radar comprising: a radio wave transmitter and a receiver; an antenna array including a plurality of antennas arranged at non-uniform intervals, the antenna array being configured to receive echoes of a transmitted radio wave reflected from a target wherein each of the plurality of antennas provides a received signal; and at least one signal processor and associated circuits configured to provide: a correlation matrix generator generating an autocorrelation matrix for the received signals; an eigenvalue calculator which calculates a plurality of eigenvalues of the autocorrelation matrix; an extractor which estimates a number of echo arrivals to the antenna array based on the plurality of eigenvalues, and which extracts, from a plurality of eigenvectors respectively corresponding to the plurality of eigenvalues, at least one eigenvector corresponding to a noise component; a spectrum calculator which calculates a MUSIC spectrum based on the at least one eigenvector; a tested azimuth setter which extracts, from the MUSIC spectrum, a number of peaks, and which sets a number of azimuths corresponding to the number of extracted peaks as a number of tested azimuths, the number of tested azimuths being greater than the number of echo arrivals by a preset number; a determiner which determines a level of correlations among a number of steering vectors respectively corresponding to the number of tested azimuths; a power-estimation target selector which selects, from the number of tested azimuths, a number of azimuths as power-estimation targets based on the determined level of the correlations among the number of steering vectors; a first estimator which estimates a received power level from each of the power-estimation targets; and a second estimator which estimates, from the power-estimation targets, an azimuth of the target based on the estimated received power level from each of the power-estimation targets, the estimated received power level estimated by the first estimator being equal to or greater than a preset threshold level.