A Method to Eliminate the Influence of Noise on Ocean Wave Observation by Coherent X-band Radar

Abstract

The invention discloses a method for eliminating the influence of noise on coherent X-band radar observation of sea waves, which relates to the technical field of marine remote sensing. Spectrum analysis is used to obtain parameters such as peak period and main wave direction; the second part is to select the Vennian spectrum as the empirical spectrum, establish a model for minimizing the difference between the empirical spectrum and the observed spectrum, and solve the model to invert the effective wave height of ocean waves. The invention solves the problem that the coherent X-band radar cannot accurately observe the ocean wave information in the prior art, and provides a new technical basis for the research on near-shore ocean activities and ocean dynamic environment.

Description

technical field [0001] The invention relates to the technical field of ocean remote sensing, in particular to a method for eliminating the influence of noise on coherent X-band radar observation of sea waves. Background technique [0002] Ocean wave is an important ocean dynamic parameter, which is of great significance to the research of marine science. Traditional observation methods (such as buoys, etc.) cannot fully reflect the real sea conditions in the sea area to be measured, and are vulnerable to damage; satellite remote sensing (such as satellite altimeter, synthetic aperture radar) can observe surface currents over a large area, but its time resolution is limited by the repetition period of satellites. The limitation of the observation period is long; the navigation X-band radar has high time and space resolution, and can perform all-day and all-weather observation. In recent years, it has been widely used to observe ocean waves, such as the patent number ZL2013101...

AI Technical Summary

Problems solved by technology

Traditional observation methods (such as buoys, etc.) cannot fully reflect the real sea conditions in the sea area to be measured, and are vulnerable to damage; satellite remote sensing (such as satellite altimeter, synthetic aperture radar) can observe surface currents over a large area, but its time resolution is limited by the repetition period of satellites. The limitation of the observation period is long; the navigation X-band radar has high time and space resolution, and can perform all-day and all-weather observation. In recent years, it has been widely used to observe ocean waves, such as the patent number ZL201310123693. The published navigation X-band radar wave parameter inversion algorithm based on EOF decomposition; but because it has not been calibrated, it is very inconvenient for actual use; coherent X-band radar can directly obtain the Doppler frequency shift of the sea surface without After calibration or introduction of complex modulation transfer function, it is suitable for observation of ocean waves

[0003] Compared with the navigation X-band radar, the coherent X-band radar system is affected by the correlation noise when imaging the sea surface. The noise of the radar image is large, which has a great impact on the observation of ocean waves.

The existing method for eliminating noise is to utilize the frequency dispersion relation to design a bandpass filter to filter the image spectrum (such as the shore-based X-band broadband coherent radar ocean wave information extraction technology research and patent No. published by Cai Wenjuan are CN106093936A, Wang Shuyao, Zhou Tao et al. The current information extraction method based on the coherent radar slow-sweep mode) was published to separate the wave energy from the background noise, but because a single band-pass filter cannot completely eliminate the noise, and the modulation transfer function is affected by sea conditions, radar parameters, Due to the influence of various factors such as observation geometry, it is not easy to determine accurately, and there is still a large deviation in the inverted wave parameters

Therefore, it has become the technical field to invent a simple and feasible method for eliminating the influence of noise on coherent X-band radar images to solve the problem that the system noise of coherent X-band radar in the prior art is large and cannot accurately observe ocean wave information. Urgent technical problems to be solved

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