Navigation X-wave-band radar wave group detection method based on wave theory

Abstract

The invention discloses a navigation X-wave-band radar wave group detection method based on a wave theory. The navigation X-wave-band radar wave group detection method based on a wave theory includes the steps: performing empirical orthogonal function decomposition on a navigation X-wave-band radar image sequence, selecting a main modal to reconstruct a wave field, and obtaining the wave surface displacement of different positions in an observed sea area through scaling of the wave field; for the wave surface of one radial direction, utilizing change of the displacement gradient to detect the extreme value of the wave surface, and according to the difference between adjacent two maximum values and minimum values, obtaining the wave height at different positions; utilizing the sum of two sine functions to fit the wave surface between the adjacent minimum wave heights, and identifying the area as a wave group when the fitting parameter accords with the wave theory; and combining with observations at different times, obtaining the parameters of the wave group, such as amplitude, length and group speed. The navigation X-wave-band radar wave group detection method based on a wave theory utilizes the buoy to perform scaling on the main modal of the wave field so as to obtain the wave height information of a large area in the observed sea area, and then utilizes the two sine functions which are approximate in frequency based on the wave theory to determine the wave group without requirements for selecting a threshold according to the experience, and has the advantages of being simple and easy to do, and being wide in the application range.

Description

technical field [0001] The invention belongs to the technical field of marine remote sensing, and relates to a wave group detection method for navigation X-band radar image sequences based on wave theory. Background technique [0002] A wave group is a superposition of a series of simple waves with close frequencies moving in the same direction. Wave groups can excite the resonant frequency of offshore structures, causing serious damage to offshore platforms, breakwaters, and ships. Furthermore, the velocity of wave energy in the ocean is equal to the velocity of the wave group. Therefore, the monitoring of wave groups is of great significance to marine engineering and marine scientific research. [0003] The traditional wave group observation method is to use instruments such as buoys to continuously measure the wave surface at a fixed point, and then analyze the measured values ​​to obtain wave group parameters. The disadvantage of this method is that it can only measur...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for extracting wave group parameters by using the navigation X-band radar image sequence, so as to solve the problems in the prior art that the navigation X-band radar image can only obtain local wave heights and need experience to select the threshold, which has become the technical field. urgent problems in

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