A Novel Method for Estimating Number of Radar Targets Exploiting Mainbeam Subspace Structure

Ryuhei TAKAHASHI  Kei SUWA  Takayuki INABA 

Publication
B - Abstracts of IEICE TRANSACTIONS on Communications (Japanese Edition)  Vol.J89-B  No.7  pp.1124-1130
Publication Date: 2006/07/01
Online ISSN: 1881-0209
Print ISSN: 1344-4697
Type of Manuscript: Special Section PAPER (Special Issue on Radio Application Technologies in Observation, Positioning and Detection)
Category: 
Keyword: 
radar,  angle measurement,  monopulse,  subspace,  eigenvector,  mainbeam,  AIC,  MDL, 

Full Text(in Japanese): PDF(1.1MB)

Summary: 
Monopulse angle measurement is widely used for radar angle tracking. However, it is inherent that monopulse method can only estimate direction-of-arrival for single source. Therefore degradation of performance will occur in a situation that multiple sources are impinging in mainbeam. Recently, for tracking radar system, angle measurement method for multiple sources impinging in mainbeam using superresolution method has been studied. One can consider new radar angle tracking scheme which uses angle measurement method following to number of targets. To this end, estimation of signal number receiving in mainbeam is crucial for selecting the method and for performing superresolution method when multiple signals are detected. In radar, it is obvious that target signals will arrive at mainbeam region since the signal is reflected wave from target that is illuminated by transmitted electromagnetic wave. In this paper, we proposed that a novel method for estimating number of radar target signals exploiting subspace structure of steering vectors within mainbeam. An algorithm of proposed method is shown followed by an example. Also performance of proposed method comparing with AIC and MDL by numerical simulation is shown. The result indicates that proposed method has combined performance of beamspace-AIC and MDL.