Research In Geological Hidden Danger Areas With Olique Aerial Photography Technology

Oblique aerial photography is a new type of technology that has developed rapidly in recent years.Compared with the traditional single-camera aerial photography technology,this technology can not only obtain top surface information of ground objects,but also collect high-resolution side texture information of the same objects as well.To fully illustrate the application potential of oblique aerial photography in the field of remote sensing geological disaster investigation,this paper 1)chooses the mouth area of Daninghe in the Three Gorges Reservoir of China as the research area where the mountains are steep,dangerous and sometimes difficult for investigators to reach;2)studies how to obtain oblique data and carry out data processing;3)studies how to utilize oblique data to identify geological hazards as well as how to improve its accuracy and efficiency.Conclusions are drawn as follows:(1)Based on the feature of oblique aerial photography equipment and the technical regulation of remote sensing geological disasters investigation,this paper adopts tight coupled airborne POS direct geographic positioning technology as well as precise point positioning technology to perform oblique multi-view image aerial triangulation.With the participation of little ground control points,the aerial triangulation accuracy of the study area can meet 1:2000 scale mapping requirements through feature point extraction,relative geological orientation,connecting point matching,regional aerial triangulation.(2)With the real 3D model generated from oblique data,geological disasters such as landslides,some obvious dangerous rocks,collapses and debris flows can be easily identified.Furthermore,some hidden dangerous rocks which lie in steep mountains,impossible for traditional remote sensing method to recognize and sometimes difficult for people to reach can also can identified.And comprehensive quantitative analysis such as length,width,height,area,slope and volume can be performed to various types of geological disasters based on real 3D model.With oblique aerial photography technology,the accuracy and efficiency of geological disaster investigation can be improved,and field investigation will be reduced significantly.(3)The manned oblique aerial photography equipment can be used to carry out large-scale investigation with high accuracy.Therefore,it is more suitable for large-scale remote sensing geological disaster investigation in such areas: 1)areas which is hard to do field investigation;2)steep mountains or valleys;3)areas that have little effective satellite coverage as the result of clouds.As a new type data with high quality,the oblique data is a good choice for remote sensing geological disaster investigation.The application of oblique aerial photography technology in remote sensing geological disaster investigation has absolutely great potential.