Signal Detection Based On Multiple GPS Satellites Information Fusion

Instead of transmitting the signal itself,the target detection system based on the non-cooperative illuminator use the third-party illuminator to detect target through the reflection echo or shadow effect of signal,the mechanism of this detection system determines it works "silently".compared with traditional detection system.it has potential gains such as anti-reconnaissance and strong survival ability.GPS is a kind of easily accessible illuminator as a result of eight GPS satellites are continuously in view anywhere and at any time on earth.So GPS signal can be used as the non-cooperative illuminator for target detection.This paper studies the GPS-based non-cooperative illuminator target detection method,the main work can be summarized as follows :(1)This paper presents a weak echo detection method based on multiple GPS satellite data fusion.Firstly,Concerning the problem that the DPI and MPI of surveillance channel can not be effectively suppressed because of GPS signals mixing into the reference channel,the proposed method separates and reconstructs the multi GPS reference signals of the reference channel based on SIC algorithm,and obtained the purified reference signal that can effectively suppress the DPI and MPI in the surveillance channel based on the ECA algorithm.Secondly,As the target reflection echo signal is too weak to detect,the proposed method integrats the multiple detection statistics through the coordinate transformation algorithm.This processing enhance the detection statistics peak through data fusion agorithm.Finally,Based on the analysis of the statistic,the adaptive detection threshold and the theoretical detection performance are obtained.The simulation results show that the proposed method can effectively detect the weak echo signal of the target in multiple GPS satellites as the non-cooperative illuminators scenarios.(2)This paper presents a signal shadow detection method based on multiple GPS satellites information fusion.Firstly,Due to the local signal is too short that can't obtain the anti-noise performance when local signal correlates with received GPS signal,This method constructs the detection statistic by the differential coherent accumulation,which can effectively improve the detection performance and avoids the rollover of the GPS navigation data bit during the accumulation process.Secondly,As the statistic is not applicable to the CA-CFAR detector,this method estimates the mean value of the detection statistic according to the maximum value of the mean value of the detection statistic's upper and lower envelope,this method uses the estimated value to reverse the detection statistic,so that the detection statistic is applied to the CA-CFAR detector to achieve the effect of the adaptive detection;Finally,In order to make the target detection more reliable,this method puts the multi-channel decision results into the fusion detection algorithm,and obtains the final decision results.The simulation results show that the proposed method can effectively detect the shadow effect of the signal in multiple GPS scenarios.