A new approach to improve the accuracy of the angle measured in multi-target situation for OTH radar

The sum and difference amplitude comparison method of a secondary surveillance radar is conventional in azimuthal direction indication but is effected by much azimuthal errors, especially by the multiple-targets situation. After a discussion of azimuthal estimation techniques and performance, with special reference to the OTH HF radar applications, a novel estimation, which is called MSMWSA (method of symbol maximum and weighted sidelobe averaging), for this radar is described. The proposed technique is a close approximation of the maximum likelihood estimator (MLE) taking into account the receiver characteristics as well as the multiple-targets situation. The performances, obtained by analysis and computer simulation, are compared with those of a traditional estimator.<>