Research And Analysis Of Ambiguity Of Synthetic Aperture Radar And Its Application In Ship Detection

Synthetic Aperture Radar SAR(Synthetic Aperture Radar,SAR)is a kind of microwave imaging radar,because of its all-day,all-weather,and superior penetration,it has been widely used in reconnaissance,mapping,marine resources testing,natural resources survey and other fields.Fuzziness is one of the important parameters of synthetic aperture radar.In the detection of targets,when the energy of the fuzzy area is too high,it will produce false targets and seriously affect the SAR image quality,which will have a great impact on the application of SAR images,,thereby affecting the ship target detection accuracy.In this paper,it started with analyzing the causes of azimuth ambiguity and range ambiguity.Because SAR has developed a variety of modes:Stipmap mode,Spotlight mode,scan mode.The calculating of azimuth ambiguity and range ambiguity in Spotlight mode,scan mode is different from the mode of Stipmap mode.And then this paper introduces a new method to the calculate azimuth ambiguity in these new modes.In the processing of analyzing the SAR raw data,a detection method based on the azimuth ambiguity zone location to remove the false ship target is proposed.By analyzing and calculating the azimuth ambiguity value and combining with the characteristics of the false image,the position of the blurred area in azimuth is identified and the false target is identified.Finally,the validity of the method is verified by real data analysis,and the accuracy of ship detection is improved.At the same time,the paper puts forward the calculation method of distance from range fuzzy area to target area,and application based on it.Finally,the effectiveness and feasibility of the proposed method are proved by experiments.It provides a new idea for SAR image target detection under certain conditions,such as port area target detection and ship target.