A method and system for precise positioning of a lunar lander with improved libration parameters

Abstract

The invention relates to a precision lunar lander positioning method and a precision lunar lander positioning system capable of improving libration parameters. Initial data are inputted, and the approximate coordinates of a lander are adopted as the initial coordinates of the position of the lander; aiming at each baseline, theoretical observation values of delayed observations of VLBI (very long baseline interferometry) are calculated according to the initial coordinates of the position of the lander, partial derivatives of the delayed observations with respect to the position of the lander and partial derivatives of the delayed observations with respect to lunar libration parameters are calculated and compose a coefficient matrix, a model is jointly created aiming at the position of the lander and the lunar libration parameters, least square calculation is carried out aiming at the parameter vectors of the model, moreover, whether a calculation result meets a condition of convergence is judged, if so, then the result is outputted, and if not, then iteration is carried out again until the condition of convergence is met. On the basis of creating the observation module for VLBI observation data, the invention firstly puts forward and creates a new model which simultaneously estimates reference system connection parameters (lunar physical libration) and lander positioning parameters, thus remarkably increasing the positioning precision of the lunar lander.

Description

technical field [0001] The invention belongs to the field of lunar lander positioning and deep space exploration, and in particular relates to a precise positioning method and system for a lunar lander with improved libration parameters. Background technique [0002] For the lunar exploration project, the position information of the lunar lander is very important, so the determination of the position of the lunar lander is the key technology and difficult problem of the entire engineering project. Obtaining accurate position information of the lander and controlling the relevant orbit of the lander directly affects whether the lunar lander can enter the predetermined design orbit as planned, and has an important impact on the development of various subsequent scientific experiments. [0003] In my country's lunar exploration project, VLBI (very long baseline interferometry, very long baseline interferometry) is used as the main lander positioning technology. [0004] See th...

AI Technical Summary

Problems solved by technology

[0012] However, prior information on many geometric and physical model parameters involved in the observation model of each observation technique of the lunar lander, if directly used without improving the accuracy of the prior information, will be propagated to the determined lunar lander lander in position

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