STAP Application For High Frequency Radar

High Frequency Over The Horizon Radar (HF-OTHR) has attracted much attention in recent years for its properties of large scale and long distance. Two important performances are the clutter suppression and the targets detection. Space-Time Adaptive Processing (STAP) algorithm as a new algorithm for the clutter suppression, has been one of the hot topics in the research of the HF-OTHR. And STAP algorithm has been applied in the airborne radar system.The purpose of this study is to find out a suitable STAP algorithm for the HF-OTHR system.Firstly, we analysed the correlation of the first-order sea clutter and the ionospheric clutter in the HF-OTHR using the measured data. By the results of analysis, we considered that the first-order sea clutter was homogeneous locally, the"point"ionospheric clutter was non-homogeneous, and the"strip"ionospheric clutter was homogeneous.Secondly, we simulated the ground clutter in the airborne radar system, the first-order sea clutter and the ionospheric clutter in the HF-OTHR system. Then we tried to suppress these three kinds of clutter using the Fully STAP algorithm. The results showed that the Fully STAP algorithm could suppress the clutter efficiently., but it was not a robust algorithm.Finally, we introduced the Joint Domain Localied algorithm (JDL), the Direct Data Domain algorithm (D3) and the Hybrid algorithm. We also discussed how to choose the training data. For the JDL algorithm, we proposed the conception of the Protected Frequency Units and the JDL algorithm was improved. For the D3 algorithm, the idea of truncating the Coherent Integration Time (CIT) was proposed. And we combined the two ideas for the Hybrid algorithm. By comparing the three algorithms in the performance of clutter suppression and the computational load, the improved JDL algorithm has a bright future in the application for the HF-OTHR.