Microvibration detection and compensation for SDGSAT-1 based on line-by-line bundle adjustment

Microvibrations degrade the geometric quality of optical Earth observation satellite imagery by introducing intra-scene spatial distortions, necessitating robust detection and compensation strategies. Like many optical Earth observation satellites, the Sustainable Development Goals Science Satellite 1 (SDGSAT-1) faces similar challenges. To address this, this paper presented a novel microvibration detection and compensation framework based on line-by-line bundle adjustment for SDGSAT-1. By minimizing directionally weighted residuals of a modified rigorous imaging model—constructed from tie points (TPs) and virtual ground control points—the framework enabled high-temporal-resolution estimation of microvibrations, parameterized through the discrete attitude microvibration model, via least-squares optimization. A new sensitivity indicator was also proposed to evaluate the adequacy of the weighting scheme for microvibration detection during optimization and to guide the dynamic adjustment of TP weights. Applied to SDGSAT-1 data, the method successfully characterized microvibrations at 1.0 Hz in the along-track direction and 0.4 Hz in the cross-track direction for the first time. Experimental results demonstrated that the proposed framework effectively suppressed microvibration-induced geometric distortions, consistently outperforming both raw imagery and classical approaches: it achieved a 33.16% reduction in RMSE compared to uncorrected data and improved cross-track precision by 27.82% over the conventional method. The impact of charge-coupled devices operating at heterogeneous imaging speeds was evaluated, with results showing no significant degradation in detection performance. These results validated the framework's effectiveness in enhancing geometric accuracy through robust microvibration modeling and compensation. • A LLBA-centered microvibration detection and compensation framework was presented. • A new indicator (SI) was proposed to guide TP weight adjustment. • First along-track microvibration of SDGSAT-1 detected at 1.0 Hz. • First cross-track microvibration of SDGSAT-1 detected at 0.4 Hz.