Research On Waveform Design Of Incoherent Scatter Software Radar Based On Composite Coding Technology

With the development of science and technology,human exploration of the earth is not limited to the ground and the sky,but also gradually began to study the ionosphere.Incoherent scatter radar(ISR),the most powerful ground-based device for ionospheric detection,is rapidly developing.ISR has the advantages of high detection accuracy,wide detection range and high range resolution.The detection principle of incoherent scatter radar is to receive the weak signal scattered by the thermal fluctuation of the ionosphere particles,so that many parameters of the ionosphere can be inverse calculated,such as electron density,electron temperature and ion temperature and so on.Because the scattered signal is very weak,powerful signal processing methods and various complex coding schemes are needed to meet the needs of practical use.Therefore,based on the existing three coding methods of incoherent scatter radar and the theory of coding ambiguity function,two new composite codes with high range resolution are explored in this paper.Finally,the ambiguity function in the data processing system is debugged using the measured data of AMISR(The Advanced Modular Incoherent Scatter Radar).The main contents of this paper are as follows:Firstly,the development status of the incoherent scatter radar and its coding technology is introduced.Then the detection principle of incoherent scatter radar is introduced and the expressions of four ambiguity functions and their conversion relations are deduced.Secondly,based on the theory of ambiguity function,the two-dimensional ambiguity function of three traditional codes(long pulse code,the Barker code and the alternating code)are modeled and their performance is analyzed.Subsequently,the performance of several composite codes is tested,and two excellent composite codes(the alternating code modulated by the complementary code and the alternating code modulated by the m-sequence)are explored,and their two-dimensional ambiguity function are modeled and their performance is analyzed.Finally,the detection range,range resolution and the anti-noise performance of these codes are compared and analyzed,and a conclusion is drawn.Thirdly,the main module functions of the data processing system of the incoherent scatter radar are introduced,and the ambiguity function part of the data processing system is adjusted by using the AMISR measured data.In the data processing system,the measured data of the AMISR are processed by replacing different ambiguity function and the ionospheric parameters are compared with the data on Madrigal’s official website and IRI(International Reference Ionosphere)model,so as to select an ambiguity function with the minimum error and apply it to the data processing system.