SENSOR ORIENTATION FOR HIGH-RESOLUTION SATELLITE IMAGERY: FURTHER INSIGHTS INTO BIAS-COMPENSATED RPCs

As high-resolution satellite imagery (HRSI) attracts usage in a broader range of mapping and GIS applications, so the demand for higher 3D accuracy increases. One of the notable recent innovations in sensor orientation modelling for HRSI has been bias compensated RPC bundle adjustment, which has shown that geopositioning to high accuracy can be achieved with minimal ground control; indeed, only one control point may be required. Bias-compensated RPCs and related issues are further examined in this paper, with attention being paid to the impact of terrain height variation and the issue of scanning mode. Image scanning characteristics can significantly influence metric performance, with the effect being more pronounced for HRSI sensors that dynamically vary their orientation during scene capture. Through experimental testing with IKONOS and QuickBird stereo imagery, the authors demonstrate that bias-corrected RPCs are capable of yielding sub-pixel geopositioning from base-level imagery products. Thus, bias-compensated RPCs are not only favourable in regard to optimising accuracy capability; they also offer cost advantages.