Simultaneous Estimation of Precession and Spin Rate of Space-Instable Target Based on Photometric Sequence

Abstract

The invention discloses a method for simultaneously estimating the precession and spin rates of a spatial instable object based on a luminosity sequence, and the method comprises the steps: obtainingthe luminosity sequence of the spatial instable object; carrying out the variational mode decomposition of the luminosity sequence into a plurality of intrinsic mode functions; calculating the mutualinformation of each intrinsic mode function and the luminosity sequence; extracting the intrinsic mode function frequencies corresponding to the two maximum mutual information values as the spin frequency and precession frequency of the spatial instable object, and converting the spin frequency and precession frequency of the spatial instable object into the precession and spin rates of the spatial instable object. According to the invention, the method employs VMD (variational mode decomposition) for the mode decomposition of the luminosity sequence, achieves the effective extraction of the spin frequency and precession frequency of the object based on the mutual information theory, can achieve the simultaneous estimation of the target precession and spin rates at higher precision, and solves a problem that a spectrum analysis method, an autocorrelation method and a cross residual error method are insufficient in estimation capability for the rotation state of a spatial object. The method provides a new reference idea for the estimation of the rotation state of the spatial object.

Description

technical field [0001] The invention relates to a method for simultaneously estimating the precession and spin rate of a spatially unstable target based on photometric sequences, belonging to the field of computing. Background technique [0002] With the acceleration of human development and utilization of outer space, a large number of man-made objects are operating in near-Earth space. Due to debris collisions, satellite failures, and in-orbit failures, tens of thousands of abandoned space objects have been produced, posing a great threat to space security. Abandoned targets in low orbit will be affected by forces such as aerodynamic moment, gravity gradient moment, and geomagnetic moment, and will not re-enter the atmosphere and burn down after several years to decades; abandoned high-orbit spacecraft in crowded orbital space, if no active measures are taken , which will always exist. On-Orbit Serving (OOS), which mainly focuses on spacecraft fueling, on-orbit maintenan...

AI Technical Summary

Problems solved by technology

In recent years, based on the spectral analysis method, autocorrelation method and cross residual method of the target photometric sequence, the rotation state of the space target has been inverted. Periodically select two frequencies with high energy in the frequency spectrum as the frequency of spin and precession, and approximate the precession period. The frequency multiplication appears in the estimated frequency spectrum of the spin frequency, and the estimation error is large; the cross residual method is compared with The advantage of the autocorrelation method is the most obvious, but it is greatly affected by the sampling frequency

It can be seen from the inversion results that the above method can only perform independent inversion of precession or spin rate. For an unstable space target whose photometric sequence contains two frequencies at a certain moment, the photometric sequence obtained from ground-based observations, The precession and spin frequencies included in the photometric series cannot be determined simultaneously for the following reasons:

[0004] 1) Spectrum analysis method, cross residual method and autocorrelation method cannot perform simultaneous inversion of target spin and precession rate, and can only estimate one rate in spin or precession alone

[0005] 2) During the decomposition process of Empirical Mode Decomposition (EMD), the frequency aliasing is serious, and its modal number is adaptive and uncontrollable; the frequency doubling of the spectral analysis method is serious, and the estimation error of the target rotation rate is relatively large

[0025] For the complex photometric sequence of the space target, this method has no obvious difference in frequency spectrum peak value obtained by spectrum analysis, autocorrelation analysis and cross residual analysis, and the peak distribution is not concentrated. The applicability of this method is not strong. If the distance between the peaks is multiplied, the method will not be able to select the rotation rate of the target

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