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Research On Radio Frequency Interference Suppression And Target Tracking In High Frequency Surface Wave Radar

Posted on:2018-02-25Degree:MasterType:Thesis
Country:ChinaCandidate:J Z HanFull Text:PDF
GTID:2348330515489858Subject:Circuits and Systems
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The high frequency ground wave radar(HFGWR)has been widely used as an ef-fective means to detect both marine parameters and ships or low altitude aircrafts.In the field of sea detection,researchers have proposed many superior performance algo-rithms and results are consistent with the buoy,therefore the use of HFGWR to detect marine parameters has been recognized.Compared with sea monitoring,target detec-tion technology is lagging.The advantage of HFGWR target detection is that it can monitor targets of exclusive economic zone(EEZ)over the horizon and in real time,and achieving full range of monitoring when it cooperate with the sky wave radar.At the same time there are many problems to be solved,such as radio frequency interference(RFI)caused by a large number of radio station reduce radar performance seriously,the first-order sea echo covers ship signal,target missed alarm rate is large,and the direction of arrival(DOA)estimation is inaccurate if radar system employs compacted antenna.To solve these problems,this paper studied target detection and tracking algorithm of HFGWR,researched on RFI suppression,detection algorithm,parameter estimation,tracking algorithm and track association,and then gived algorithm results of measured data.The data comes from multi-station radar networking experiment which radar and signal processing laboratory of WuHan University did in Fujian Zhangzhou.The radar detection area is Taiwan Strait,and receiving antenna is made up of two monopole/crossed-loop antennas.Each radar station is equipped with automatic iden-tification system(AIS)for comparative verification.Specifically,the research work of this paper is listed as follow:1)This paper proposed a spatial domain decomposition algorithm for RFI suppression.This paper analyzed the form of RFI in radar signal processing and classified the common RFI,then use the azimuth of the interference to suppress RFI by spatial decomposition after the first Fourier transform,it requires that the number of inter-fering sources be less than the number of antenna arrays in a sweep cycle.A large number of echo data show that 1 to 2 interference sources are more common,so 3 antenna array elements is reasonable.2)This paper designed a constant false alarm detector for HFGWR target detection,and analyzed the reason of target missed detection.Distance estimation result and radial-velocity estimation result of the HFGWR are relatively accurate,but antenna pattern distortion results in some azimuth estimation error,the azimuth of the target near the distorted position is estimated to the distortion of the pattern.3)Two kinds of motion state equations are established.The state variables are distance,radial-velocity and radial-acceleration.The azimuth of each measurement is only used as a reference for data association,so that targets can be separated from the space to reduce misinterpretation,and avoid the influence of azimuth error on the tracking filter simultaneously.4)This paper proposed an algorithm to improve the estimation accuracy of azimuth using track association of two radar stations.When two radar detect the same target simultaneously,target azimuth can be calculated according to the distance.This paper proposed a hypothesis to judge whether the track is associated,first,assume that two tracks are from the same ship,calculate the ship's speed and course,then judge whether the next measurement to meet the equations of motion,finally came to a conclusion,calculates the azimuth of target according to the distance in the associated track.
Keywords/Search Tags:High Frequency Ground Wave Radar, Radio Frequency Interference Supression, Target Detection, Target Tracking, Direction of Arrival Estimation
PDF Full Text Request
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