Marine radar image rainfall identification method based on K parameter

Abstract

The invention provides a marine radar image rainfall identification method based on the K parameter. The K parameter is defined as 100 times of the specific value of the zero intensity percentage to the echo intensity mean. Firstly the offline observation experiment is performed, data statistical analysis is performed and the detection threshold T is determined, and then same-frequency interference suppression processing is performed on the radar original image to be identified; then the shielding area zero intensity percentage and the echo intensity mean are calculated and the K parameter isdetermined; and finally the K parameter is compared with the detection threshold T so as to determine whether the image is the rainfall image. The effect is verified by using the actually measured data. The accuracy of the rainfall image identification method is higher than that of the method using the echo intensity mean and the diversity factor for 16.6% and higher than that of the method independently using the zero intensity percentage for 3.4% so that the radar rainfall image in the marine process can be more accurately identified, and the wave inversion error caused by the rainfall can be reduced.

Description

technical field [0001] The invention relates to a method for identifying rainfall in marine radar images based on K parameters, which belongs to the technical field of marine remote sensing, in particular to the technical field of marine remote sensing in which images acquired by marine radar are used to identify rainfall on the sea surface. Background technique [0002] Ocean waves are the ocean phenomenon that is most closely related to human beings. The monitoring of ocean waves is of great significance to navigation safety and marine resource management. Marine radar can be used to monitor marine environment information. Using its echo images, marine dynamic parameters such as wind, wave, and current can be extracted, and many wave information such as wave spectrum, wave height, wavelength, wave direction, and wave period can be retrieved. However, there are many noises in radar echo images that affect the accuracy of ocean wave monitoring, mainly including co-channel in...

AI Technical Summary

Problems solved by technology

The zero-intensity percentage method was proposed by Lund[13] et al. in 2012. It counts the percentage of zero-intensity pixels in the image to identify the rainfall image, and its statistical area is the entire radar image. However, this method is easily affected by sea conditions, and its accuracy is affected by limit

The above methods use the characteristic parameters of radar images for rainfall identification, but none of them take into account the influence of radar echoes caused by sea conditions on rainfall identification

In 2015, Xiang Tuo [14] carried out a specific design based on the zero intensity percentage, and used the zero intensity percentage in the occlusion area for rainfall image recognition, but only used a single parameter of the radar image, and did not make full use of other characteristic parameters of the radar image , there are defects such as strong chance and poor accuracy

Although the above methods are also using the characteristic parameters of the radar image for rainfall identification, they are not related to the method of rain identification using the K parameter of the occlusion area in the present invention, see references [8-14] (Hao Yanling, Tang Yanhong, Lu Zhizhong. X-band Research on Noise Detection and Filtering Methods of Maritime Radar Image[J].Remote Sensing of Land and Resources.2008,20(2):14-17.Zheng Yaneng.Research and Design of X-band Maritime Radar Image Preprocessor[D].Harbin Engineering University Master's Degree Thesis. 2010:1-3. Yang Xuelin. Design and Implementation of Radar Raw Image Noise Preprocessing Software [D]. Master's Degree Thesis of Harbin Engineering University. 2013:21-24. Shen Jihong, Li Ying, Dai Yuntao, etc. X- Identification and suppression of rainfall interference in band radar images. Optical Precision Engineering. 2012, 20(8): 1846-1853. Zhao Hui. Method and implementation of noise suppression in X-band radar sea clutter[D]. Master of Harbin Engineering University Paper.2014:9.Lund B,Graber H C,Romeiser R.Wind Retrieval From Shipborne Nautical X-Band Radar Data[J].IEEE Transactions on Geoscience and Remote Sensing.2012,50(10):3800-3811P.Xiantuo.Radar Research on image denoising technology and software design of wavemeter [D]. Master's degree thesis of Harbin Engineering University. 2015:1-3,31-40.)

[0005] Aiming at the problems of low recognition accuracy and the influence of sea conditions on rainfall recognition in the prior art, the present invention discloses a navigation-based Rain recognition method of radar image K parameter, K parameter is 100 times the ratio of zero intensity percentage and echo intensity mean value in the occlusion area of ​​marine radar image

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