A Space-time Enhanced Music Algorithm for Hf Radar

In this paper we propose a new algorithm to estimate the direction of arrivals (DOAs) of superimposed cisoidal radar echos from far-field targets. A potential practical application of this algorithm is high frequency ocean surveillance radar (HFOSR) detection of slow moving targets embedded in temporally correlated sea clutter that has a continuous spatial spectrum. The improvement provided by this algorithm is based on use of a state space model that more accurately represents the received high frequency (HF) Doppler radar array signal prior to spatial processing such as MUSIC. A 2-D (spatial and temporal) pre-filtering matrix is structured and applied to the received array signal, which is finally combined with the high-resolution (MUSIC) method for DOA estimation. Higher resolution and lower detection threshold are achieved by this algorithm compared to conventional beam-space MUSIC and sensor-space MUSIC. Both the theory and simulations verify the effectiveness of our proposed algorithm.