A Method of Retrieving Ocean Wave Parameters Using a Single Shipborne X-band Radar Image

Abstract

The invention discloses a method for inverting sea wave parameters by using a single ship-borne X-band radar image, comprising the following steps: selecting an inversion area, collecting a grayscale image by the X-band radar, and selecting areas with the same distance and different azimuth angles 1 and area 2; interpolate the gray value of the radar image in area 1 and area 2 into the Cartesian coordinate system, and then perform Fourier transform to obtain the wave number spectrum of area 1 and area 2, and find area 1 Calculate the peak wave number and peak wave direction of area 1 and area 2 according to the peak value of the respective wave number spectrum of area 2 and its corresponding wave number component; calculate the peak wave number and peak wave direction according to the wave number spectrum of area 1 and area 2; judge And eliminate the ambiguity of the direction of the peak wave direction; select the direction near the main wave direction, integrate its gray value, and obtain the relevant wave parameters. This method collects grayscale images in real time, and calculates and analyzes the extracted relevant parameters, so that the changes of sea wave parameters can be obtained in real time.

Description

technical field [0001] The invention belongs to the technical field of marine remote sensing, and in particular relates to a method for retrieving sea wave parameters by using a single ship-borne X-band radar image. Background technique [0002] Ocean waves are one of the most common ocean phenomena, which have an important impact on the safe navigation of ships and the planning of routes. The commonly used wave observation method is wave buoy, but it can only obtain the wave changes at local points or lines, and generally needs to be anchored to a fixed position, and cannot be used for shipboard observation. Remote sensing technology is also used to observe ocean waves. The satellite wave spectrometer is a new type of ocean wave spectrum observation instrument, which has the advantages of a large observation range, but its products are immature and have low time and space resolution, which cannot meet business applications. Coherent and non-coherent X-band radars are widel...

AI Technical Summary

Problems solved by technology

These methods all require a sequence of images observed by the radar over a period of time, usually a sequence of 32 or 64 images. When the signal-to-noise ratio of the radar is low, 512 images are required, which reduces the real-time performance of the observation data; In addition, the navigation of the ship will also cause the position of the observation area to change continuously, and the traditional modulation transfer function is not applicable, which brings great difficulties to the real-time observation of waves, and the real-time performance of observation parameters is very important for the safe navigation of the ship.

Therefore, inventing a simple and feasible method for inverting sea wave parameters using a single ship-borne X-band radar image to solve the problem in the prior art that only long-term X-band radar image sequences can be used to invert sea wave information Become an urgent technical problem to be solved in this technical field

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