無人飛行載具(Unmanned Aerial Vehicle, UAV)於要求精度之圖資測製應用時，因飛行高度較低並可在雲下飛行取像，與大型載具相比可更機動性獲取空間解析度較高之影像，雖無法如大型載具酬載大像幅感測器供大區域圖資製作，但於小區域之圖資更新卻相當適合。但一般UAV因酬載重量限制，僅可酬載體積小且重量輕之感測器，如非量測型相機及低精度定位定向系統，即AHRS系統。因此，本研究嘗試在UAV上酬載Trimble BD970 GNSS OEM GPS接收模組，此GPS接收模組體積小且重量輕可安置於UAV上，並透過VBS-RTK GPS定位技術獲取UAV精確飛行軌跡資訊，再經時間內插相機曝光瞬時的GPS資訊供空中控制使用，輔助UAV影像空中三角測量(簡稱空三)平差，以降低地面控制點需求。
但欲引入GPS觀測量供空中控制使用必須考量GPS天線與相機投影中心偏移量之問題，但因UAV所酬載之非量測型相機，將造成此偏移量不易透過地面測量方式測得，於本研究將於空三平差時使用線性漂移參數克服此偏移量無法量測之問題；此外，UAV所酬載之非量測型相機，相機參數乃透過地面近景攝影測量以自率光束法平差方式率定所得，但率定所得相機參數無法完全描述相機在航拍取像時的情況，故本研究於空三平差將採用自率光束法克服相機參數率定不完全之問題。實驗中，首先確定GPS模組BD970在VBS-RTK GPS定位技術下在地面高速移動時可獲得高精度的定位成果；接續驗證線性漂移參數及自率光束法平差於此研究的適用性；最後亦探討不同地面控制點配置及來源對空三平差之精度探討，並提出1/5000基本圖圖資測製精度要求下，VBS-RTK GPS輔助UAV影像自率光束法空三平差的地面控制點最適配置。 / UAV(Unmanned Aerial Vehicle) is currently used in civil purpose such as mapping and disaster monitoring. One of UAV advantages is to collect images with high resolution for mapping demand. However, due to payload limitations of UAV, it is difficult to mount metric aerial camera and precise POS(Positioning and Orientation System) device. Instead, only the non-metric camera and the low accurate AHRS (Attitude and Heading Reference System) can be installed. For mapping demands, Trimble BD970 GNSS OEM board will be carried on the UAV to collect the high accurate flying trajectory as control information for AT (aerial triangulation) by VBS-RTK(Virtual Base Station - Real Time Kinematic) GPS technique. Meanwhile self-calibration bundle adjustment will be employed for AT(Aerial Triangulation) to overcome the imperfect calibration of non-metric camera by the close-range photogrammetric approach. The precise offset between image perspective center and GPS antenna center, called GPS antenna-camera offset, is hard to measure in centimenter level by terrestrial measurement approach. Therefore the drift parameters will be utilized to solve the problem of GPS antenna-camera offset while performing bundle adjustment with self-calibration for AT of UAV images. In the experiments of this study, the height positioning accuracy of BD970 by VBS-RTK GPS approach at high speed movement will be proved firstly. Then the adaptability of drift parameters and self-calibration for GPS supported AT of UAV images will be verified. Finally, the accuracy of AT by using different control information will be analized and appropriate configuration of GCPs(Ground Control Points) for VBS-RTK GPS supported self-calibration bundle adjustment for AT of UAV images will be proposed under the mapping demand with the scale of 1 : 5000.
| Identifer | oai:union.ndltd.org:CHENGCHI/G1002570021 |
| Creators | 李敏瑜, Li, Min Yu |
| Publisher | 國立政治大學 |
| Source Sets | National Chengchi University Libraries |
| Language | 中文 |
| Detected Language | English |
| Type | text |
| Rights | Copyright © nccu library on behalf of the copyright holders |
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