Gravity-gradient-invariant-based method for estimating orbit element

Abstract

The invention provides a gravity-gradient-invariant-based method for estimating an orbit element. The method comprises: step one, carrying out preparation work; step two, carrying out decomposition of an ideal gravity gradient tensor under an east-noth-up (ENU) coordinate system and obtaining feature values; step three, solving decomposition of a measuring epoch J2 model gravity field tensor under the ENU coordinate system and obtaining feature values; step four, solving all measuring epochs r and phi by using feature values of a J2 gravity gradient matrix; step five, calculating an initial orbit element by using the r and phi; and step six, carrying out orbit element smoothing. Therefore, with utilization of the gravity gradient matrix invariant information measured during the satellite operating process, a geometrical distance between the satellite and the earth's core and the latitude of the earth's core are obtained by iterative solution; a measurement equation that uses a semi-major axis, an eccentricity ratio, an orbit inclination angle, a perigee depression angle, and a true anomaly in an orbital element as state parameters is provided by using an obtained data as an observed quantity; and a perturbation kinetic equation of the orbital element is introduced innovatively and five orbital elements are estimated by using a batching least square method. The gravity-gradient-invariant-based method has advantages of high autonomous degree, high anti-interference capability, and low building cost and the like and has advantages that the traditional method does not have in the deep space exploration field.

Description

An Estimation Method of Orbit Elements Based on Gravity Gradient Invariant technical field The invention provides a method for estimating orbital elements based on gravity field gradient invariants, which relates to a method for estimating orbital elements of satellites in orbit using gravity field gradient measurement data, and belongs to the field of navigation technology. Background technique The earth's gravitational field is the space range affected by the earth's gravity, but due to the irregularity of the mass distribution inside the earth, the earth's gravitational field is not a force field that changes according to a simple law. In order to establish the Earth's gravity field model, traditional physical geodesy has formed and developed a series of gravity field theories and methods based on the observation data collected on the Earth's surface, such as gravity potential, gravity potential function, and geoid. Due to the limitations of observation methods, the Ear...

AI Technical Summary

Problems solved by technology

When the detector is far away from the earth, continuing to use the traditional ground station for remote orbit determination will cause problems such as weak signal strength, serious delay, and various interferences, which will bring great difficulties to the real-time orbit determination of deep space detectors.

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