After the target positions are determined within the lidar dataset , they can be compared with the gps surveyed control coordinates. table 2 (a) and (b) illustrate the errors found at the target locations in strip#1 and strip#2, respectively. the errors are the differences between the target coordinates in the lidar data and gps surveyed coordinates. the table also contains the standard deviation values of the detected differences,as provided by the target determination algorithm.
the detected differences show a vertical error in both strip#1 the targets fall below their gps-measured coordinates on average by 8 cm, the vertical error detected at the target locations in even larger for strip #2, on average 15 cm. these determination, which indicates that these detected differences are indeed significant. However,the detected horizontal coordinates of the targets in the lidar data cannot be considered significant for most of the targets, as they fall within their standard deviation values , except at one or two targets.