MUSIC algorithm implementation for shipboard HF radio direction finding

A high-resolution, high-frequency direction finding system for shipboard applications based on the multiple signal classification (MUSIC) algorithm has been developed. The half-rack system has successfully undergone at-sea and pier-side tests on several ship classes, and at several field sites. Using a 3- to 5-m antenna aperture, the system demonstrates groundwave line-of-bearing accuracies of ±3° over the full HF band (3 to 30 MHz) at shore sites and ±5° on ships. The system effectively operates against skywave and groundwave signals, calculating the elevation and azimuth angle of the incoming wave front. For shipboard applications, three-element bow and stern antenna arrays overcome the typical field deformations caused by superstructure interactions. A detection and selection algorithm selects the best array based on field uniformity and signal-to-noise ratios. Spatial smoothing and sector search pattern algorithms help to reduce re-radiation effects