Academic literature on the topic 'Photogrammetric Triangulation'

Abstract. This study aims to introduce triangulation and ToF measurement techniques used in three-dimensional modelling of cultural heritages. These measurement techniques are traditional photogrammetry, SfM approach, laser scanning and time-of-flight camera. The computer based approach to photogrammetric measurement that is named SfM creates dense point cloud data in a short time. It is low-cost and very easy to application. However traditional photogrammetry needs a huge effort for creating 3D wire-frame model. On the other hand active measurement techniques such as terrestrial laser scanner and time-of-flight camera have also been used in three-dimensional modelling for more than twenty years. Each one has specific accuracy and measurement effectiveness. The large or small structures have different characters, and require proper measurement configurations. In this study, after these methods are introduced, their superior and weak properties in cultural heritage modelling to make high accuracy, high density and labour and cost effective measurement.

For use in glaciological research, between 1982 and 1984, we succeeded in surveying and mapping the Mount Gongga Glacier, on a scale of 1:25 000, by means of a combination of terrestrial and aerial photogrammetry. This paper describes the method in detail. In the survey area, we set up an independent, triangulation network, with microwave distance measurement, and two, independent, straight-line traverses, for basic control. Control points were observed by intersection. The terrestrial, photogrammetric baselines were projected and corrected into distances on the. plane of the map. Terrestrial photography accounted for the majority of the photographs of the survey area. Surveying and mapping of planimetrie and topographic features were completed on a stereo-autograph, using plates mainly from terrestrial photogrammetry. Where these data were insufficient, they were supplemented by aerial photography, plotted on a photographic plotting instrument. Orientation points of the aerial photographs were established by terrestrial, photogrammetric analysis and located on the map by an optical, mechanical method. The practical result showed that a combination of terrestrial and aerial photogrammetry, in mapping a high, mountain, glacier area, on a large scale, is more feasible and flexible than other methods and more economical as well.

For use in glaciological research, between 1982 and 1984, we succeeded in surveying and mapping the Mount Gongga Glacier, on a scale of 1:25 000, by means of a combination of terrestrial and aerial photogrammetry. This paper describes the method in detail.In the survey area, we set up an independent, triangulation network, with microwave distance measurement, and two, independent, straight-line traverses, for basic control. Control points were observed by intersection. The terrestrial, photogrammetric baselines were projected and corrected into distances on the. plane of the map.Terrestrial photography accounted for the majority of the photographs of the survey area. Surveying and mapping of planimetrie and topographic features were completed on a stereo-autograph, using plates mainly from terrestrial photogrammetry. Where these data were insufficient, they were supplemented by aerial photography, plotted on a photographic plotting instrument. Orientation points of the aerial photographs were established by terrestrial, photogrammetric analysis and located on the map by an optical, mechanical method.The practical result showed that a combination of terrestrial and aerial photogrammetry, in mapping a high, mountain, glacier area, on a large scale, is more feasible and flexible than other methods and more economical as well.

Unmanned Aerial Vehicles (UAVs) are still an interesting and current research topic in photogrammetry. An important issue in this area is determining the elements of exterior orientation of image data acquired at low altitudes. The article presents selected mathematical methods (TGC, TIC, TAD) of estimating elements of exterior orientation for image data obtained at low altitudes. The measurement data for the experimental test were recorded by the Unmanned Aerial Vehicle platform Trimble UX-5. In the framework of the test photogrammetric flight, the authors obtained 506 images and navigation data specifying the position and orientation of the Unmanned Aerial Vehicle. As a result of the research, it is proven possible to show the usefulness of the mathematical models (TGC, TIC, TAD) in estimation of elements of exterior orientation.