Research On Ship Detection Based On Wide Band Signal For High Frequency Ground Wave Radar

High Frequency Ground Wave Radar can be used as an excellent transmission effect of sea water can be achieved over-the-horizon detection; it can make up for the shortcomings of the other radars, so HFGWR has a good prospect. Because the operating frequency of this radar is always 3~30MHz, the bandwidth of the radar signal is determined by the radar's operation frequency, so the bandwidth can not choose very large. Because of the relationship of the bandwidth and range resolution ratio, the range resolution ratio can't be very large can be sure. However, in recent years, the demand for the sea information is larger than before, for the radar , the bandwidth of the signal should be increased, at this situation more sea situation can be obtained.This paper principally introduces FMPCW signal waveform parameter and the method of processing ,then through the radar system's discuss the issue of signal waveform, and then introduces the theory of the signal receiving and processing. This paper particularly analyses the difference of the processing of wide bandwidth and narrow bandwidth. This paper analyses the cause of the wide bandwidth's range defocus and velocity defocus's issues. This paper particularly introduces three auto-focus methods, they are Map Drift ,PGA(Phase gradient auto-focus technique) and Minimum entropy method. Contrast these three auto-focus methods, then this paper chooses the PGA technique to resolve the defocus of the situation of the wide bandwidth, and then resolve the good result.The resolving power of the signal and interference ability between wide bandwidth signal and narrow bandwidth signal are respectively analyzedThis paper processes the actual measurement data, analyses the result between the actual measurement data and simulation data. At last this paper prove the correctness of this method.