基于自适应窗长STFT的空间目标振动特性反演

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关键词：空间目标；时序光度；自适应窗长；短时傅里叶变换;频率特性反演中图分类号：O439；TP731 文献标识码：Adoi：10. 37188/OPE. 20253317.2810 CSTR：32169.14.OPE.20253317.2810

Inversion of vibration characteristics of space target based on adaptive window length STFT

YU Kai，HUANG Pu，LI Yuzhe，DONG Haoqing，ZHANG Xuguo （Beijing InstituteofSpaceMechanics&Electricity，Beijing1Ooo94，China） * Corresponding author，E-mail： zxg-ltt@l63.com

Abstract： Time-series photometric signals from spaceborne targets contain rich information about their operational states. Conventional short-time Fourier transform（STFT） uses a fixed window length，which limits time-frequency resolution and reduces efectiveness for target classification and identification.To address this limitation，an eigenfrequency inversion method based on an adaptive-window-length STFTis proposed. A hybrid loss function—combining minimum information entropy，peak energy contrast，and background noise level—is formulated to drive a dynamic window-length adjustment strategy，enabling adaptive matching between window parameters and signal nonstationarity. A dedicated simulation apparatus was developed to acquire time-series photometric signals that reflect space-target operational characteristics.By varying the momentum-wheel rotational states，scenarios of on-orbit steady operation and attitude adjustment were simulated，producing high-rate photometric signals induced by surface vibration. Experimental results show that the proposed algorithm achieves high frequency resolution，with eigenfrequency inversion precision of 0.4Hz ，and dynamically adjusts window length to provide multi-scale temporal resolution. The steady-state eigenfrequency of momentum wheels was estimated with error below 0.3Hz ， and transition points associated with changes in operational conditions were accurately identified. The method ofers substantial value for assessing space-target operational state，monitoring health status， and providing early fault warnings for attitude-control systems.

Key words： space targets; temporal luminosity； adaptive window length; short-time Fourier Transorm; inversion of frequency characteristics

1引言

随着近地轨道航天器数量的快速增长，太空环境竞争日趋激烈，空间态势感知作为保障太空资产安全的关键技术，其战略价值日益提升[1]。（剩余12646字）