近景攝影測量網形優化設計

Abstract

由於數位相機長足的發展以及數位影像處理技術的進步，近景攝影測量的應用已日漸廣泛。相較於航空攝影測量，近景攝影測量以較近距離拍攝物體，並可彈性地擺設測站位置，利用光軸交會之攝影幾何有助於獲致有效涵蓋區域並提供良好測量網形。理論上，採用數位相機並搭配適當的資料化算系統，即可進行近景攝影測量，然若作業參數及網形幾何未臻理想，其結果常無法滿足該項任務所需達成的物空間定位品質。 本研究主要目的在提供一基於精度要求、作業彈性及合於實用之近景攝影測量網形解算及調變平台，針對所設定應達成之定位品質要求，進行原始網形解算及調變。透過物像對應的網形平差計算，以內、外部精度指標來反映定位品質並診斷待補強或可再弱化之作業參數，而後依網形分析獲致之影響強弱順序或依作業環境設定之調變順位調變網形內容，並進行重複解算及調變，直到符合定位品質要求。藉由此解算平台，近景攝影測量工作可在設計階段完成有效的測量規劃，並且滿足物點定位品質要求。

As the rapid development of digital cameras and digital image processing technology, close-range photogrammetry has been recently widespread into various applications. Close-range photogrammetry, as compared to aerial photogrammetry, features in imaging objects in a much closer distance and is of high flexibility in placing camera stations and with convergent optical axes supporting a favorable bundle intersection. In theory, the use of digital camera together with appropriate data acquisition would activate close-range photogrammetry up to an operational level. However, most of time, users still suffer from not knowing how or whether the operating conditions would be satisfactory and reach the expected quality. The purpose of this research is to provide a platform where the optimization of close -range photogrammetric network design is to be realized. Based on the initial conditions and the required accuracy at the input of a close-range photogrammetric task, several quality indicators are applied to check if accommodations in strengthening or weakening the current network are necessary. In an iterative fashion through adjustment approach, the platform would not stop the modifications until meeting the required accuracy quality. The proposed platform, upon empirical tests, is found to be practically effective when carrying out close-range photogrammetric tasks, especially when it comes to assure the expected accuracy simply at the plan stage of actual field surveying.