Research On Imapact Of Wind Turbine On Target Detection Performance Of HFGWR

Since the 1970 s,high-frequency ground wave radar technology has become more and more mature.And breakthroughs have been made in the application of ocean state monitoring and target detection.The used scale is also growing around the world.On the other hand,as a clean and sustainable energy source,the wind power industry has also made considerable progress.Some studies have pointed out that the presence of wind turbines will seriously interfere with the target detection performance of radar,include high-frequency ground wave radar.The increase in the number of wind farms and the expansion of scale make the problem worse.Therefore,it is of great significance to study the influence of wind turbines on the detection of high-frequency ground wave radar targets.At the same time,this research can also provide theoretical support for wind farms to choose sites more scientifically.First of all,based on the characteristics of wind turbine's rotation and high-frequency ground wave radar's signal,this paper maked a physical modeling of wind turbine by using the knowledge of target scattering point superposition theory.From the signal processing,the echo model of the wind turbine's blades under single frequency signal and chirp wave is obtained.After analyzing the wind turbine echo signals from the perspectives of RangeDoppler,distance spectrum and time-frequency,the effects of several simulation parameters on the wind turbine echoes are analyzed.Secondly,based on the experiments in 2018,the analysis of the experimental data confirmed the existence of wind turbine echo and verified the correctness of the wind turbine echo simulation results.Analysis confirms the impact of wind turbines on target detection.First,wind turbines may be incorrectly identified as targets by radar.Second,by comparing the ratio of the number of target matches to the number of AISs in the blocked and unblocked areas of the wind turbines,it was confirmed that the probability of detection in the blocked area of the wind turbines was reduced.Last,based on the statistical analysis of ships' power,a method for evaluating the influence of wind turbine array on target detection of high frequency ground wave radar is proposed in this paper.Firstly,it is proved by radar equation that the radar cross section of target is equal to the product of radar receiving target echo power and attenuation factor.Because of the consistency of attenuation factor's influence on Bragg echo power and target echo,the target echo power could be compensated by the statistical distance curve of Bragg power.By comparing the RCS of the target vessel passing through the sheltered and non-sheltered areas of the wind farm to represent the shadowing effect of the wind farm.