| The ionosphere as an important component of the terrestrial space, directly affectsradio, communication, positioning and navigation activities. Incoherent ScatteringRadar (ISR) has proved to be the most powerful ground-based instrument for theexploration of the ionosphere. Hence it is of great significance to investigate the signalprocessing algorithm and software implementation for Incoherent Scatter Radar.Based on the Incoherent Scatter Radar Signal Processing System Design, the signalprocessing algorithm and the software implementation for Incoherent Scatter Radar areintensively discussed in this paper. Firstly, the detection principle and the signalprocessing scheme of the Incoherent Scatter Radar are studied. With the theory ofambiguity function, the autocorrelation function of the ionospheric plasma is derived.Then, using the ambiguity function and the lag profile matrix, the processing algorithmsof the long-pulse code, the Barker codes and the alternating codes (AC) are studied. Theadvantages and disadvantages of the three coding types are comparatively analyzed.According to the cumulative property of the alternating codes, decoding the alternatingcodes with integer lags and fractional lags are presented in detail, and the lag resolutionbecomes better for the alternating codes with fractional lags. Subsequently, the signalprocessing algorithm for Incoherent Scatter Radar is realized based on the ADSPTS201S, including the digital down conversion, the post detection filtering, theautocorrelation function, the power profile and the power spectrum calculations. Inorder to improve the calculation speed, the DSP program is optimized by rationallyallocating the memory and taking advantage of the dual-computation blocks. Finally,the stability and the real-time characteristic of the system are verified with the actualtest. According to the analysis of the experimental results, the validity of the algorithmis also verified. |
PDF Full Text Request