Wind Direction Inversion And Practicability Research Of Algorithm Of Underwater Bottom Topography Detection Based On Sar Image

SAR (Synthetic Aperture Radar) is one of the important sensors of microwave remote sensing, and it is used in many fields of ocean researches. Shallow underwater topography SAR image detection is one of its ocean applications. Wind direction in SAR imaging time is one of the important parameters of shallow underwater topography SAR detection, and it was determined by experiences in the past. A new method named the maximum correlation coefficient method which uses shallow underwater topography in wide gridding and its SAR image to determine wind direction is presented firstly in the paper, and is testified by wind direction inversion of SAR images of ShuangZi reef. After determining the wind direction, shallow underwater topography of ShuangZi reef SAR image simulation and inversion researches are done in the paper by using shallow underwater topography SAR detection model and algorithm.For the tide and tidal current numerical calculation area of ShuangZi reef is too small and short of harmonic constants of tide, it is divided into three parts: the whole South China Sea (SCS), the middle part of SCS and the sea area of ShuangZi reef in the SAR image simulation of ShuangZi reef. The calculation's results of the large area are regarded as the primary conditions of calculation of the small area. The simulation SAR images of ShuangZi reef in the different micro-scale wave directions (wind direction) are calculated, based on the tide and tidal current calculation, and the effect of the micro-scale wave direction to SAR image is analysed.Shallow underwater topography of ShuangZi reef is detected by one scene ERS-1 SAR image and two scenes RADARSAT SAR images based on its SAR image simulation. Their inversion results have preferable precision, the mean absolute error is 4.36m and the mean relative error is 12%. SAR image simulation and inversion of shallow underwater topography of ShuangZi reef testify the practicability of SAR image simulation and inversion model and algorithm of shallow underwater topography, and establish the foundation of SAR operation detection of shallow underwater topography.