Sea Clutter Sharpening And Target Detection For The Sky-surface Radar

The sky-surface radar, which adops the mixed mode of skywave transmitting and surface wave receiving, combines the advantages of both skywave radar and ground-wave radar. However, the sky-surface radar will also suffer bistatic radar angle, ionospheric effects of pollution and multi- mode, so that sea clutter Bragg frequency of broadening severe flooding low-speed ship targets may affect detection. Meanwhile, the high- frequency radar for the detection of maneuvering target world, is also facing the target due to the mob ility caused by Doppler broadening and a plurality of target separation and other issues. To solve these problems, this paper makes the following work:This paper introduces the days of- mixing formula system to collect sea clutter Bragg frequency, and thus to a wide beam characteristic spectral broadening sea clutter bistatic angle caused analyzed. Find bistatic angles sea clutter caused by broadening the spectrum is small. Therefore focuses on the influence of the ionosphere on the sea clutter broadening after the basic characteristics of the ionosphere introduce qualitative analysis phase ionospheric disturbances, amplitude modulation and multi- mode broadening effect caused by the characteristics of sea clutter.Then, this paper analyzes the ionosphere p hase perturbations induced sea clutter broadening and sharpening methods. First, the introduction of time-reversible method, the presence or absence of ionospheric disturbances judgment phase. Then, introduce the phase gradient method, two methods of traditional time-domain correlation method for removing ionospheric phase perturbations by theory and simulation, analysis of these traditional methods there are two problems: First, it is difficult to extract pure exhibition adaptive wide sea clutter separation, two large phase perturbation amplitude algorithm failed. Therefore, this paper presents the distribution of PGA algorithm SVD and sea clutter and sea clutter sharpening sharpening method method based on frequency analysis and optimal path algorithm-based S-Method. By comparing the simulation and analysis of their respective advantages.Finally, this paper world Radar target detection two difficulties: the detection and complex maneuvering target detection ship targets were explored. For detection of sh ip targets, this paper proposes a detection algorithm based on wavelet transform. The use of sea clutter and ship targets at a distance and azimuth-dimensional correlation dimension differences, wavelet decomposition and reconstruction method, the target a nd clutter, which enhances SNR signal. For maneuvering target detection problem, this paper presents an improved time- frequency analysis of maneuvering target detection algorithms. For uniformly accelerated rate target and quasi- random moving target, and frequency spectrum when it crosses the plane when the algorithm can be separated and the two goals were detected. The simulation proved the effectiveness of the algorithm.