On-orbit geometric calibration and validation of Optical-1 HR

Owing to relatively simplistic domestic hardware technology and a lack of on-orbit geometric calibration, particularly interior calibration, the positioning accuracies of Optical-1 HR satellites can vary greatly depending on the presence of ground control points (GCPs). Without GCPs, accuracies are typically lower than 100 pixels, whereas when GCPs are plentiful, accuracy is higher than one pixel, demonstrating the potential for a large discrepancy between international optical satellites with the same image resolution. This study investigated a new method of geometric calibration for Optical-1 HR satellites. Experiments were conducted to demonstrate the positive effects on positioning accuracy achieved by the calibration method. After calibration by our method, a positioning accuracy of higher than one pixel was obtained with only a small number of GCPs, which is equivalent to the accuracy of advanced international optical satellites with the same image resolution.