Journal of Electronic Measurement and Instrument (电子测量与仪器学报) 2013/27:9 PP.897-905
Traditional direction finding algorithms are limited by the requirement of unwrapping phase ambiguity,so the baseline length is short and the precision can’t be improved. In order to improve the precision,the long baseline can be set. The azimuth angle can be gained by estimating the time-delay of signals between two antennas. In the channelized system of polyphase filter,the time resolution of the data is lower after the extraction and the time-delay precisions of traditional time-of-arrival estimation algorithms are worse. Because the signals launched by modern radars are always wideband signal,this paper converts time-delay estimation into frequency estimation according to the relationship between time domain and frequency domain. The precision of this algorithm isn’t limited by sampling interval. The simulation results by MATLAB and Quartus II software show that this algorithm is simple and suitable for hardware implementation. And it can be carried out in real time processing. Under the condition of certain baseline length and band width,the algorithm can achieve very high precision of direction finding.