A Spaceborne SAR System and Method for Retrieving Ocean Current Field Based on Angle Diversity

Abstract

The invention discloses an ocean current field inversion satellite-borne SAR system based on angle diversity, and a method thereof. The satellite-borne SAR system comprises two radar antennas which are arranged in the flying direction of a satellite, wherein the two radar antennas respectively generate two radar wave beams; and the two wave beams have different squint angles and can irradiate the same area on the ocean surface in different time. The method comprises: utilizing the satellite-borne SAR system and taking a doppler center frequency as the observation variable to perform inversion on an ocean current field; and obtaining a complete velocity vector of an ocean current, that is, the ocean current information obtained through inversion not only includes the radial velocity information of the ocean current but also includes the azimuth velocity information. Compared with a traditional ocean surface current field inversion means, such as field observation and shore-base radar observation, the ocean current field satellite-borne SAR system based on angle diversity can realize inversion of a worldwide ocean current field, can comprehensively know about temporal and spatial variation of the ocean current, and can work all day long and all weather without limitation of meteorological conditions.

Description

technical field [0001] The invention belongs to the technical field of ocean remote sensing, and in particular relates to an angle-diversity-based ocean flow field inversion spaceborne SAR system. Background technique [0002] Ocean currents have an important influence and restriction on the formation and change of climate and weather over the ocean, as well as various physical, chemical, biological and geological processes in the ocean. For example, ocean currents flowing from low latitudes to high latitudes will cause water vapor to be transported upwards, increasing air humidity and resulting in precipitation; while ocean currents flowing from high latitudes to low latitudes will cause temperature inversion, water vapor is difficult to transport upwards, and evaporation is weak and difficult to form. rain. In addition, ocean currents also have important military significance. For naval operations, ocean currents are one of the important factors considered in combat. Rea...

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Problems solved by technology

[0004] In order to overcome the shortcomings of existing ocean current inversion methods: for example, the existing spaceborne SAR current measurement methods cannot invert the complete two-dimensional velocity vector of ocean currents; the "on-site observation" method has limited spatial coverage, and it is difficult to fully understand the temporal and spatial changes of ocean currents ; The X-band radar can only obtain the corresponding flow field in places where the waves are larger than 1 meter and the waves are relatively uniform

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