Method for determining intersection coordinates of satellite wave beam and earth

Abstract

The invention discloses a method for determining intersection coordinates of a satellite wave beam and the earth. The method comprises the following steps of: (1) seeking a unit vector rfs of the satellite wave beam in a satellite body coordinate system; (2) calculating a conversion matrix of the satellite body coordinate system and a satellite track coordinate system by a yaw angle, a pitch angle and a roll angle of a satellite; (3) calculating the conversion matrix of a geographic coordinate system and an earth coordinate system by longitude lambda and latitude I of the satellite; (4) calculating the conversion matrix of an auxiliary coordinate system and the geographic coordinate system by an included angle beta of a meridian plane on which the satellite is and an instantaneous orbit plane of the satellite and an included angle alpha between a movement direction of the satellite and a geographic horizontal plane; (5) converting the unit vector rfs into the earth coordinate system to obtain rfe by coordinate system conversion; (6) associating a linear parameter equation of satellite beam incidence with an earth ellipsoid equation, and calculating two groups of coordinates [xje, yje and zje]T, wherein a group of coordinates near the satellite are coordinates of an intersection point of the satellite wave beam and the earth.

Description

technical field [0001] The invention belongs to the technical field of space microwave remote sensing, and relates to a method for determining the position relationship between a satellite beam and the earth. Background technique [0002] The spaceborne microwave scatterometer is a typical radar system that measures the backscatter coefficient σ° of the target. It is mainly used for sea surface wind field measurement. It is one of the important remote sensing instruments that can simultaneously measure sea surface wind speed and wind direction. When inverting the sea surface wind speed and wind direction from σ°, the longitude and latitude of the measurement point corresponding to σ° can be obtained by determining the coordinates of the intersection point of the satellite beam and the earth, and the sea surface wind speed and wind direction can be calculated after being brought into the inversion model. [0003] At present, foreign countries mainly use the method of vector m...

AI Technical Summary

Problems solved by technology

However, the relevant literature only gives the conversion result of the vector from the satellite orbit coordinate system to the earth coordinate system, without detailed conversion process and description, and this method does not explain the calculation process of the position vector difference, so it cannot be applied in actual calculations

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