A Slope-based Method for Matching Elevation Surfaces

A method is presented for the co-registration of overlapping elevation surfaces based on local slope analysis. Comparison and statistical analysis of local slope versus local elevation difference between overlapping surfaces allows for the estimation of both vertical and horizontal offsets between the two surfaces. This method is then used to re-align the flightlines of a Light Detection and Ranging (lidar) dataset collected in southern Idaho resulting in a dataset with significantly higher accuracy than the original. The relative horizontal accuracy is doubled, with a final value of approximately 25 to 30 cm, while the relative vertical accuracy is improved by several centimeters to a final value of approximately 6 to 7 cm.