Research On Slope Monitoring Technology Based On GPS Assisted Photogrammetry

In the field of pit slope monitoring, the traditional way of measuring not only needs professional measuring equipment and professional practitioners, but also needs to climb the top of the pit. There is a chance of being harmed. In recent years, close-range photogrammetry technology is developing rapidly. However, the professional cameras are expensive and complicated to operate, restricting the development of photogrammetry. This research will use an ordinary digital camera to develop close-range photogrammetry. Meanwhile, the development of GPS measurement technology is also changing. Combining the advantages of GPS measurement technology, the slope monitoring system of GPS and photogrammetry technology has practical significance.This paper researches the slope monitoring system of using GPS and photogrammetric techniques. The main contents and achievements are as follows:(1)Chosing the markers and finding the method to put those markers on the slope surface, using some operators to extract the feature points on the photos captured on-site were important. After experiments of point extracting, a principle of identifying and highlighting the center of mark will be set to eliminate the operators can’t identify the mark and then analyzing the reasons. The best operator will be selected.(2)The monitoring system was developed on the base of principles of close-range photogrammetry theoretical. The system can solve the extraction of feature points, select the feature points, calculate the feature point coordinates and so on.(3)The monitoring system (JSPh) was used on one of the pit in Qixia District. The coordinates of control points were measured by GPS. After entering the GPS date in the system, the system will run according to the processes and obtain the coordinates of feature points. Then using the coordinates of feature points were calculated by the system as the control points, solving the remaining coordinates of feature points. Comparing the coordinates of feature points by calculating with the previous period feature point coordinates, then slope displacement will be obtained.(4)The functions of JSPh will be extended, using the SIFT operator to match each group of photos were used in the monitoring system, and then exporting the matching results of each group. Then using cylindrical projection transformation to stitch all photos, the final panoramic view will be getted.