Pixel Screening, Filtering Method and System for Wind Vector Inversion in Rainfall Situation

Abstract

The invention provides a pixel screening and filtering method and system for wind vector retrieval under precipitation situations. The pixel screening method comprises the steps of correcting interference of precipitation on observed signals of a scatterometer to obtained a relatively accurate wind-derived radar backscatter cross section area; according to the obtained wind-derived radar backscatter cross section area, determining every fuzzy solution of the pixels in the wind vector retrieval under the precipitation situations and the total grey level of every fuzzy solution; finding out a target fuzzy solution closest to numerical wind data; judging whether the total grey level of the target fuzzy solution is greater than a preset grey level threshold; if so, marking the corresponding pixel. The filtering method comprises the steps of screening the pixels in the wind vector retrieval under the precipitation situations through the pixel screening method. Due to the fact that the interference of the precipitation on the observed signals of the scatterometer during the screening process, the pixels with relatively large wind vector retrieval errors can be effectively eliminated, and the precision of the wind vector retrieval can be improved.

Description

technical field [0001] The invention relates to the field of ocean remote sensing, in particular to a pixel screening and filtering method and system for wind vector inversion under rainfall conditions. Background technique [0002] Sea wind is an important dynamic factor acting on the surface of the ocean. It drives ocean movements at various scales from surface waves to deep ocean current systems. The small ones form ocean waves, and the large ones promote the development of ocean currents. Sea breeze adjusts the sea-atmosphere coupling by regulating the exchange of heat, water vapor and chemical substances between seawater and the atmosphere, and maintains global and regional climate models. This coupling has an important impact on global and regional climate, and can even cause global environmental changes, such as the El Niño phenomenon. Moreover, sea breeze can be integrated into regional or global numerical weather prediction systems to improve the ability of weather...

AI Technical Summary

Problems solved by technology

Due to the observation characteristics of the SeaWinds scatterometer (rotary scanning of the disk antenna), the inversion error (the second step in the inversion step) of the ambiguity solution of the sub-satellite point area of ​​the scatterometer is generally large, so the data in the circle used In the filtering algorithm, the number of pixels with large inversion error in the filtering window is often more than half, which makes the filtering effect of the number in the circle poor and makes the final inversion error high

[0005] The current wind vector inversion algorithm can well solve the sea surface wind vector inversion task in most cases (95%), but there are still situations where the inversion error is relatively large: rainfall, near-shore wind field and high wind speed

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