Beamspace ML bearing estimation incorporating lowangle geometry
Abstract
A problem in lowangle radar tracking,, namely, bearing estimation in the presence of a strong specular multipath component that arrives within the beamwidth of the direct path signal, is studied. Threedimensional beamspace domain maximum likelihood (3DBDML) is a computationally simple ML bearing estimation algorithm applicable in this scenario which operates in a 3D beamspace. A variation of 3DBDML incorporating the multipath geometry as a priori information is presented. In symmetric 3DBDML the pointing angle of the center beam is equal to the bisector angle between the direct path ray and the image ray, which may be estimated a priori given only the radar height and the target range. The effect of the inclusion of a priori information on the performance of 3DBDML is analyzed in terms of the dependence on the relative phase difference between the direct and specular path signals, the sensitivity to error in the bisector angle estimate, and the results of operation when no specular multipath component is present in the data. In addition, computationally simple schemes for coherently incorporating multifrequency data into 3DBDML are investigated.
 Publication:

IEEE Transactions on Aerospace Electronic Systems
 Pub Date:
 May 1991
 DOI:
 10.1109/7.81426
 Bibcode:
 1991ITAES..27..441Z
 Keywords:

 Bearing (Direction);
 Computerized Simulation;
 Maximum Likelihood Estimates;
 Multipath Transmission;
 Radar Tracking;
 Collimation;
 Error Analysis;
 Communications and Radar