Marine Target Detection Technology Based On A New Generation Of Civilian Satellites

Passive detection radar using electromagnetic wave radiated by non-cooperative radiation source in space.And by receiving and processing the electromagnetic wave signal which is re-irradiated by the target and the direct wave signal transmitted by the radiation source to the radar,the detection of the target in a certain area is realized.Because of the characteristics of silent reception,bistatic,and the wide range of the electromagnetic wave signal,the passive detection radar has the incomparable advantage to the conventional active radar.For example: four-anti characteristics,not easy to be detected by the enemy,lower cost,no electromagnetic pollution,and so on.It is a very broad prospects for the development of radar systems.Nowadays,the ocean has become the source of power for the development of human beings,and the sea power has become one of the main interests of all countries.When the naval ship performing tasks,also need to escort ship radar equipment,timely detection of the threat from enemy.All the civil satellites studied in this paper refer to civil communication satellites,and the technology of shipborne passive radar based on civilian communication satellite radiation source is studied.But the detected targets do not include targets such as high speed mobile and maneuverable missiles.In this paper,first introduce the ABS-S satellite communication standard,and then determine the form of the outbound signal.And the feasibility analysis is carried out: The existing satellite resources in China is introduced,through the discussion of fuzzy function to measure the communication satellite signal range resolution and velocity resolution,and the detection range was discussed,when the radar working in the forward scattering region,the target area(RCS)increase dramatically.Using the Zhongxing-ninth communications satellite as an example,and simulation using MATLAB,the results show that the system has good range resolution and velocity resolution.When radar working in the forward scattering region,signal-to-noise ratio of echo signal is very low,brought great challenges to the target detection method.Secondly,a marine target detection technique based on civilian communications satellite radiation source is proposed.The main steps are as follows: Direct wave reference signal is obtained by direct wave reference antenna,and receiving echo signal by echo receiving antenna.These signals are processed by high frequency amplifier,down conversion and analog digital conversion(ADC);Using ECA-B algorithm to eliminate the direct wave interference signal of each echo signal;Because the target echo signal is weak,the time required for coherent accumulation is very long.The target has been moving in this time,resulting in a problem of delay/doppler walking.So it is necessary to process the echo signal by keystone transform to eliminate the delay/ doppler walking problem;And then echo signal is processed by the delay-doppler cross correlation with the corresponding direct wave reference signal;Then the coherent accumulation is used to improve the signal to noise ratio.At last,the constant false alarm detection algorithm is used in the 3D graph,which is used to obtain the target information.Then,it focuses on the keystone transform.The keystone transform is generally used in the active detection radar,this paper introduces it into the shipborne passive radar based on civilian communication satellite radiation source,and gives the theoretical derivation and simulation.Then,the key technologies of sea target detection based on civil satellite are simulated and analyzed by using MATLAB simulation.In the fifth chapter,this paper summarizes the shortcomings of this paper and prospects for the future work.