Field Testing Experiment And Algorithm Improvement Of Signal Processing System For Incoherent Scatter Radar

The ionosphere is an important part of the earth's atmosphere, which has an important influence on broadcast, television, wireless communications, measurement, navigation and space exploration. The study of ionospheric characteristics is of great significance. The Incoherent Scattering Radar (ISR) is an effective tool in detecting and researching on the ionosphere. The ionosphere is a soft target, to achieve the effective detection of its characteristics, the use of the form of the transmitted signal and the corresponding signal processing methods are different from conventional radar. In this thesis, with the development of China's first incoherent scattering radar, the related field test experiments are carried out. In order to solve the main problem, the debugging and the corresponding algorithm improvements are made. The work of this thesis is of great significance and practical value for improving the performance of the Incoherent Scatter Radar system of China.Firstly, the principle and basic techniques of Incoherent Scatter Radar are studied. By analyzing the generating process of scattering spectra of the ionosphere, the incoherent scatter detection principle is discussed. The characteristics of the scattered signal are analyzed, and the noise calibration method is given. With the analysis of ambiguity function, the autocorrelation function of the ionospheric plasma is derived. As a key concept in signal processing, the definition of lag profile matrix is presented. And the calculation method of the autocorrelation function and the power spectrum of ionospheric plasma are studied.Secondly, China's first Incoherent Scatter Radar is discussed, including the design, function and realization method of signal processing system etc. The focus is played on the detailed discussions on the DSP debugging method of the main board and the subboard.Finally, three typical signal codes, such as the long-pulse code, the Barker codes and the two-phase alternating codes, are studied in detail. These coding types and their characteristics are analyzed by simulation. The advantages and disadvantages of the three coding types are analyzed by comparing their ambiguity functions. On the basis of this, the implementation the signal processing algorithms is studied based on ADSP-TS201, and some improvements are made. The problems encountered in the algorithm improvement and the corresponding solving methods are discussed in detail. The experimental results are compared with the simulation results to verify the correctness and effectiveness of the proposed algorithm.