A precise calculation method for the position of spaceborne GNSS-R specular reflection point

Abstract

The invention discloses a method for accurately calculating the position of a satellite-borne GNSS-R mirror reflection point, comprising: step S1, calculating and obtaining an initial position point of a mirror reflection point according to the position point T of the GNSS satellite and the position point R of the receiver satellite S; step S2, calculate the initial incident angle α t and the initial reflection angle α r ; Step S3, according to the initial incident angle α t and the initial reflection angle α r Angle size relationship, one-way adjustment of the vector direction; step S4, calculate a correction incident angle α t1 and a corrected reflection angle α r1 ; Step S5, repeat the above steps S3-S4 until the angular relationship between the incident angle and the reflection angle is reversed; Step S6, use the angle dichotomy method between the vector and the vector, repeat the angle dichotomy for multiple iterations, until the Fresnel is satisfied The exact position S of the specular reflection point is obtained final . The invention can quickly and accurately extract specular reflection points.

Description

technical field [0001] The invention belongs to the technical field of navigation signals and signal processing, in particular to a method for accurately calculating the position of a satellite-borne GNSS-R mirror reflection point. Background technique [0002] The technology of using GNSS reflection signal (Global navigation satellite system reflectometry, GNSS-R) to carry out earth remote sensing is a new type of satellite remote sensing technology, which can be used for sea surface height, sea surface wind field (including sea surface wind speed and wind direction), soil humidity, etc. application field. [0003] The specular reflection point is defined as the reflection position of the shortest path among all possible paths from the transmitter to the receiver through the ground reflection. Accurate estimation of specular reflection points is a key issue in GNSS-R remote sensing, which is mainly reflected in: (1) In the forward scattering model of GNSS reflected signals...

AI Technical Summary

Problems solved by technology

The main problem is that the existing specular reflection point estimation algorithms all assume that the normal and radial coincidence of any point on the WGS 84 reference ellipsoid, and judge whether the convergence condition of the Fresnel reflection theorem is met through this assumption

Therefore, using the WGS 84 reference ellipsoid model, but assuming that the normal direction of each point on the spherical surface coincides with the radial direction, and then using the radial direction instead of the normal direction when judging the convergence conditions, the mirror reflection point estimation method is used to accurately calculate the position of the mirror reflection point will produce significant deviation

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