Development Of A Model Airplane-Borne Photogrammetric System

Displacement Monitoring is one of the essential parts in geotechnical engineering design and construction. In harsh and/or inaccessible areas, monitoring, measurement and survey using traditional methods are generally time-consuming and laborious, even impossible. It is therefore of great practical interest and prospects to develop effective, cheap displacement monitoring techniques, which are not restricted by field conditions and subjected to few aviation regulation restricts, but still have reasonably high resolution. This paper introduces such a monitoring technique, namely, a Model Airplane-Borne Photogrammetric System, recently developed by the authors. This paper concludes several aspects as follows:(1) A review of displacement measurement using Photogrammetry in geotechnical engineering is taken. Investigated the civilian application of UAV(Unmanned Aerial Vehicles ) and the feasibility of the Model Airplane-Borne Photogrammetric System is studied.(2) Based on the application of Photogrammetry in geotechnical engineering and UAV technology, the concept of a Model Airplane-Borne Photogrammetric System was proposed. A micro-model aircraft is used as platform, and a digital camera as Sensors, and then we can get information of the ground by analyze the digital image taken by the camera on the micro-model aircraft. We implement the system hardware integration, and get some amelioration during engineering tests.(3) We introduced the basic principles of photogrammetry and analytical methods. For ordinary digital cameras, the characteristics of the unknown interior elements and its big changes, big factor of optical distortion, makes it fit able to use the Bundle Adjustment with self-calibration method. Based on the ideal pin-hole model, introduced some methods for camera calibration and their characteristics. Image processing technology is introduced, and measurement of digital photo points methods are given.(4) By amending the control software, the airline can automatically match with the elevation of the ground; this will avoid the difference of scale caused hy hypsography during taking photos.(5) We have taken some low-altitude aerial photogrammetry tests and get many photos, considering that the quality of the digital images may be influenced by the undulating terrain, the curvature of the Earth, the Earth's rotation and atmospheric refraction and other factors, some correction are given, the results are satisfactory. And the tests proved that the system can be effective complete a small area, and large-scale aerial photogrammetry missions. It can be an useful supplement Satellite remote sensing Its ability to access high-resolution images, in a certain degree, is comparable with high-resolution aerial photography and remote sensing.