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The novel rotating synthetic aperture imaging system has the advantages of short processing cycle, light weight, low cost, and convenient transport, which is a potential development direction for future optical satellite payloads with ultra-large aperture. However, influenced by the coupling effects of the rectangular primary mirror, rotating imaging, and link perturbation, images from this system may have unique spatial and temporal variability with resolution anisotropy, resulting in the dynamics and weak features of targets. The insufficient recognition of system characteristics seriously restricts the application ability of corresponding target interpretation methods. To address this problem, we start with the analysis of system imaging characteristics and target interpretation mechanisms. Considering calculating texture, grayscale, and edge feature parameters in evaluation regions of different sizes, we propose a degradation assessment method based on multi-scale feature characterization. Then, combined with the theoretical calculation and practical target detection experiments, the influence of crucial parameters such as the aspect ratio and rotation angle of the primary mirror on the target interpretation capability is analyzed. The results will provide guidance for the integrated design and optimization of optical imaging systems and intelligent image processing methods. • A degradation assessment method based on multi-scale feature characterization is proposed. • The effect of rotating synthetic aperture system on image target characteristic degradation is analyzed. • The impacts of key system parameters on target detection performance are analyzed. [ABSTRACT FROM AUTHOR]

• The imaging mechanism of the novel rotating synthetic aperture system is deduced. • The image degradation model of the rotating synthetic aperture system is presented. • The effects of factors causing image quality degradation are analyzed. The Rotating synthetic aperture (RSA) is one of the most promising novel imaging systems to meet the requirements of lightweight and high resolution for optical remote sensing satellites, especially in geostationary orbit. The point spread function (PSF) orientation relative to the observed scene, intentionally changes to measure all spatial frequency information available to a filled circular aperture having a diameter approximately equal to the length of the rectangular aperture. As with all precision optical systems, RSA is also subject to dynamic disturbances from the spacecraft/environment. If not accommodated properly in the measurement and synthesis process, the dynamic disturbances can result in significant image quality degradation. To quantify methods to reduce or eliminate the errors, we first analyze the on-orbit imaging mechanism of the RSA system theoretically and then represent the worst-case on-orbit imaging degradation characteristics. [ABSTRACT FROM AUTHOR]