Research On Detection Performance Evaluation Methods For HF Surface Wave Radar

As a new radar system, the detection performance evaluation of HF surface wave radar(HFSWR) has been a research hot spot and difficult problem. On the one hand, according to the working features of HFSWR, external noise entering receiver is greater than the noise generating in receiver itself, thus the external environmental noise and interference constitute the main detection background. As the external environment and interference are in a dynamic process of changing, it makes the detection performance evaluation of HFSWR more difficult. On the other hand, as a huge system, the performance assessment of HFSWR involves a number of factors, which makes it more complicated on investigating the impact of various factors on the dectection performance reasonably. Therefore, how to evaluate the performance of HFSWR scientifically and effectively is becoming a problem of great urgency.The main propose of this thesis is to propose a effective scheme on evaluating the detection performance, which is against the difficulty of evaluation and based on the following three parts: analyzing the system components of HFSWR, summarizing the feature of detection background and researching on radar equation of HFSWR, so as to provide scientifical and trustworthy basis for decision making during the various stage of designing and using HF surface radar. The main contents are divided into two parts: forecasting power coverage and research on detection performance evaluation.In research on forecasting power coverage, the feature of ground wave propagation is analyzed and the field strength of ground wave across a rough sea is calculated using modified GRWAVE program firstly. And then the generating principle and characteristics of two main interferences among background noise, including sea clutter and environmental noise are summarized and simulation model are formed. Lastly, the SNR model for HFSWR is taking its shape from the prespective of power and taking SNR as an indicator of range detection. The results of forecasting power coverage under different environmental conditions are given via simulation and its correctness is proved by the experiment of detecting cooperative ship targets.In research on detection performance evaluation, the principle of establishing index system assessment is described firstly, and then the algorithm of analytic hierarchy process(AHP) is applied to evaluating various factors contributing to detection performance of HFSWR. However, further studies show that evualtion results using analytic hierarchy process method are of low accuracy. Thus, modern optimization technology is introduced and a improved analytic hierarchy process based on genetic algorithms is proposed. The simulation results show that this proposal of evaluation can successfully improve the robustness and credibility of evaluation results. By summarizing the whole research, a overall scheme for detection performance evaluation of HFSWR is proposed from the user’s point of view.