POS Assisted Aerial Triangulation Method for Single Flight Strip Without Ground Control Points

In scenarios such as road detection and emergency mapping, single strip photogrammetry without ground control points (GCPs) can effectively improve data acquisition efficiency. Positioning and orientation system (POS) assisted single strip aerial triangulation utilizes relative orientation to construct a strip model. However, due to factors such as cumulative errors, the strip model can experience distortion. The distortion affects the accuracy of aerial triangulation solutions and can even render the results unavailable. In addition, the attitude data from POS may not be precise enough, especially the yaw angle. To address this issue, this article proposes a POS assisted aerial triangulation method for single flight strip without GCPs. This method establishes an error correction model. By utilizing the exterior orientation elements observed by the POS system, this method corrects the less accurate position and attitude parameters obtained after relative orientation. This correction process results in obtaining high precision exterior orientation elements for the images. Moreover, the error correction model maintains a constant number of parameters, regardless of the quantity of images, with only 18 parameters, thus ensuring efficient model solving. Ultimately, through experimental validation, it has been demonstrated that the method proposed in this article has improved the overall accuracy by approximately 13.22% and 17.72% compared to traditional POS assisted bundle adjustment methods under different flight strips and varying attitude angle errors, separately.