Study of full-link on-orbit geometric calibration using multi-attitude imaging with linear agile optical satellite.

We conducted a systematic investigation into independent on-orbit geometric calibration, with the aim of applying it to linear agile optical satellite (AOS). Using a combination of multi-attitude images, a complete full-link independent calibration method chain was achieved, in which both the internal and external systematic parameters could be calibrated using the self-constraint of these images, as distinct from the absolute constraints identified from ground calibration sites. In accordance with the capacity for restraint associated with the self-constraint of the images and the geometric characteristics of the systematic errors in the imaging model, the calibration parameters that were deemed suitable for mathematical estimation under this self-constraint, as well as capable of compensating for the systematic errors, were determined by two equivalent compensations. Subsequently, a stepwise calibration for the estimation of external and internal parameters was conducted, where the corresponding points, matched from two separate combinations of multi-attitude images, were applied to the external and internal calibrations, respectively. With an aided elevation, the optimal calibration parameters were achieved under these conditions without the use of a ground control point (GCP). Finally, a set of innovative experiments were conducted on rigorously simulated data to verify the theoretical accuracy and feasibility of this method. The experimental results indicated that the method could achieve an overall theoretical accuracy of around 0.002 arc seconds, and showed good geometric consistency for all charge-coupled device (CCD) detectors.