Research On Detection And Tracking Of Ships On The River With UHF Radar

UHF(Ultra High Frequency)radar has a high resolution and a small blind range,and can realize a miniaturized antenna array.It has a broad application prospect in hydrology monitoring(such as the measurement of river velocity and discharge)and ocean dynamic parameter monitoring in coastal area,and has potential application in detecting and tracking ship targets on the water.In this paper,researches on detection and tracking of ships on the river with UHF radar are carried out.The experimental data were obtained from the monitoring of Yangtze River,in Yichang,with the coherent Doppler UHF radar named OSMAR-SU,which is developed by the radar and signalprocessing laboratory of Wuhan University.Due to the high resolution of the radar,the echo of the ship will extend in both range and Doppler dimensions to present as an extended target.Therefore,the researches in this paper also belong to the scope of extended target detection and tracking,including detection of extended target points,clustering of detected point set,direction of arrival(DOA)estimation of target,ship target tracking and so on.When detecting the extended target point,the characteristics of the river clutter are firstly analyzed,and a range-Doppler-time 3D constant false alarm rate(CFAR)detection method is proposed,which has good detection performance for the extended target in the clutter.When clustering the detected point sets,the partition is made according to the range and the extension characteristics of each partition are counted.Based on this,the number of ships is estimated by preliminary clustering,and the clustering results are optimized by subsequent adjustment and class merging,so as to obtain a reliable target center.In addition,the DOA of the target center is estimated by applying the multiple signal classification(MUSIC)algorithm,and it is found that the DOA estimation of the ship near the radar normal line(small angle)is more accurate,while the DOA estimation error of the target with large angle is larger.In the research of tracking ship target,the linear constant velocity(CV)model is selected based on experience,and the Kalman filter algorithm is adopted to track the ship target.Finally,the ship target tracks are given and the validity is proved by mutual verification of multiple parameters measured by radar.