Angle Estimation Technique Using Multi-Frequency Multi-Beam for Low-Altitude Target Tracking

When tracking low-altitude targets using radar, significant multi-path interference occurs because of their proximity to the sea surface or ground, leading to substantial errors in the monopulse angle estimation. To address this issue, this study proposes the multi-frequency multi-beam (MFMB) technique that combines the multi-frequency and multi-beam approaches. First, an optimal frequency combination is derived using linear regression to ensure that the interference patterns at different frequencies cancel one another out. Subsequently, the received signals at each frequency are synthesized, and multi-beam processing is applied to enhance the angle estimation accuracy. The simulation results confirm that the proposed MFMB method significantly reduces angle estimation errors compared with monopulse techniques, thereby contributing to improved detection and tracking of low-altitude targets in maritime and complex terrain environments.