Evaluation of beamforming and direction finding for a phased array HF ocean current radar

This paper presents a simulation-based study of the effects of beamforming (BF) and direction finding (DF) algorithms on the errors in ocean surface radial currents measurements by High Frequency Surface Wave Radar (HFSWR). They are adopted usually for phased arrays and compact arrays, respectively. In this study, both BF and DF are investigated for phased arrays. Particularly, using MUltiple Signal Classification (MUSIC) for direction finding in phased arrays is a subject which has received little attention. Through simulations of the first order sea clutter under various current scenarios, the mean RMS errors between radar-derived and simulated reference current profiles are examined extensively. A combination of using Barlett beamforming before and after Doppler processing is introduced to effectively increase the number of current estimates. The MUSIC algorithm has shown promising performance in target detection and current measurements when BF is used to first establish the maximum current velocity.