Method for calculating lunar orbit real-time in star

Abstract

The invention provides a method of on-board real-time calculation on circumlunar orbit, belonging to the technical field of real-time calculation on circumlunar orbit for spaceflights, comprising a plurality of steps: (1) take the orbit determination as the initial value and use numerical method to calculate the actual orbit; (2) select a two-body orbit as a reference orbit; (3) calculate the actual orbit in relation to the reference orbit trajectory; (4) according to the general law of relative movement between two two-body orbits, calculate a two-body orbit in relation to the reference orbit trajectory similar to the actual orbit in relation to the reference orbit trajectory; step (1) to step (4) are finished on Earth and then send the result on board; (5) the satellite, adopting the calculation method of two-body orbit, calculates real-time the orbit number of the satellite according to the two-body orbit calculated from the step (4). The method of on-board real-time calculation on circumlunar orbit has an advantage that the satellite orbit can be worked out on board in small calculation amount and also does not need to keep real-time connections with ground.

Description

technical field [0001] The invention relates to the technical field of real-time calculation of orbits around the moon by spacecraft. Background technique [0002] At present, the real-time orbit calculation on the satellite is generally only used on low-earth orbit satellites, and the method used is the flat root number orbit calculation method. The domestic spacecraft uses 19 elements for calculation, and the foreign SGP4 model is used for calculation. These two methods are similar, and both use the average orbit element and its long-term item coefficient, long-period item coefficient, and short-period item coefficient to calculate satellite instantaneous number of tracks. Since the perturbation of the J2 term of the earth's gravitational field and the perturbation of atmospheric resistance are much larger than other terms, only the J2 term of the earth's gravity and the atmospheric resistance term need to be considered when calculating the flat root number, so the formul...

AI Technical Summary

Problems solved by technology

If the traditional flat root number method is used to achieve higher-precision orbit calculations, due to the complexity of the lunar gravitational field, the lunar gravitational model used in the calculation needs to be of a higher order of about 20 orders. Under the accuracy requirements, the influence of the earth's gravitational perturbation also needs to be considered, which leads to an excessive amount of calculation and is not suitable for on-board calculations

Although the numerical solution method has high precision, it also has the problem of large amount of calculation.

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