Comparison of Horizontal Precision of Various Aerial Survey Marks in Orthophoto Production

Based on MVS-SfM algorithm, the commercial image processing software PhotoScan provides the function of automatic matching of ground marks, such as, circular, square and coded mark. However, the practical plane accuracy between the auto-matching and man-selected is not well-defined. This study is compared the plane accuracy for three types of ground marks under the same variable conditions using practical UAS photogrammetry. When the image processing with three auto-matching marks are examined as well as the wing mark is also used the man-selected to put together to compare the plane accuracy. Overall, the plane accuracy of man-selected wing mark is better than three auto-matching marks in the orthophoto. Meanwhile, the plane accuracy using square mark is better than the rest marks in three auto-matching process. The obtained accuracy result is much close to man-selected wing mark. It is recommended that choosing the auto-matching square mark can be derived the better performance in practical project implementation.