A new on-orbit geometric self-calibration approach for the high-resolution multi-linear array optical satellite based on stereoscopic image pairs

The multi-linear array pushbroom is a widely used imaging modality for high-resolution optical satellites. With the continual increase in geometric resolution and field of view (FOV), building and maintaining a calibration field with higher resolution and greater coverage will become increasingly labor- and cost-intensive. This paper proposed a simple and feasible on-orbit geometric self-calibration approach for the high-resolution multi-linear array optical satellite based on one stereoscopic image pair. The a priori geometric constraint of the stereoscopic image pair was fully utilized based on the tie points between the stereoscopic images, and between the adjacent single time-delayed and integration charge-coupled device (TDI-CCD) images, with the aid of a reference digital elevation model (DEM). By this scheme, only a small range of absolute ground control points (GCPs) covering the selected primary single (TDI-CCD) image was needed to achieve high accuracy calibration of the whole image. Experimental results indicated that the internal parameters calibrated by the proposed self-calibration approach were effective for increasing the internal relative accuracy. In this manner, we can achieve high-accuracy geometric calibration of the high-resolution and large-FOV multi-linear array optical satellite, reducing the limitations of the traditional reference calibration field, which could have great significance for future super high-resolution optical satellites.