## 5 Conclusions  
In order to improve the attitude measurement accuracy of aerospace optoelectronic platform, an attitude estimation algorithm is introduced in this paper. An adaptive threshold criterion is designed to judge whether the influence of maneuvering acceleration can be ignored. It has good flexibility and versatility because the threshold changes with the sliding of the window. DFBGA and SLAIM are applied in order to compensate for gyro drift error and maneuvering acceleration interference. A phase-lag-free LPF makes use of the phase-lead information in the higher order signal measured by gyro to revise the phase lag introduced by the attitude estimation process based on Kalman filter. The proposed method can accurately calculate the angular attitude in the presence of gyro drift and maneuvering acceleration disturbance. In addition, the phase lag can be compensated and is suitable for attitude estimation of feedback loop in high precision control system. In the simulation and experiment of signal processing, the accuracy and real-time performance of the proposed method are verified by comparing with the reference signal and the attitude measured by encoders. In the simulation of motion control, the position response tracks the position command well. The filters in proposed method does not cause the instability of the control system.  
This study improves the performance of LOS motion control system of optoelectronic platform from the perspective of sensor signal processing. The algorithm proposed in this paper does not need to change the mechanical structure design and hardware circuit design of the optoelectronic platform in practical application. This method can be applied to various optoelectronic platforms without increasing the migration cost and has strong practicability. It has the advantages of low cost and strong flexibility. In the future work, the attitude angle calculated in this study will be used as the feedback signal to complete the closed-loop of the control system, which can verify the effectiveness of the proposed method intuitively.  
Conceptualization, D.T. and Y.K.; validation, Y.K.; resources, D.T.; data curation, Y.K.; writing--original draft preparation, Y.K.; writing--review and editing, Y.W.; supervision, D.T.; funding acquisition, D.T. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Key Research Program of Frontier Sciences, CAS, grant number ZDBS-LY-JSC044, in part by the National Science Foundation of China, grant number T2122001, in part by the Changchun Science and Technology Development Plan Project, grant number 21 SH03, in part by the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine, grant number ZYCYTD-D-202001.  
Not applicable.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Common Fusion Method** & **Proposed Method** \\ \hline Roll & 0.4487 ms & 0.5189 ms \\ Pitch & 0.4346 ms & 0.5013 ms \\ Yaw & Unavailable & 0.223 ms \\ \hline \hline \end{tabular}
\end{table}
Table 6: Comparison of time required for data processing once.  
Data Availability Statement: The data presented in this study are available on request from the corresponding authors.  
The authors declare no conflict of interest.