All Articles

Most of the works of civil engineering, and some others applications, need to be designed using a basic cartography with a suitable scale to the accuracy and extension of the plot. The Unmanned Aerial Vehicle (UAV) Photogrammetry covers the gap between classical manned aerial photogrammetry and hand-made surveying techniques because it works in the close-range domain, combining aerial and terrestrial photogrammetry, but also introduces low-cost alternatives.The aim of this work is developing of an accurate and low-cost method to characterize landslides located on the size of a road.

For calibrating the camera, an accurate determination of the interior orientation parameters is needed. For more accurate results, the calibration images should be taken under conditions that are similar to the field samples.The aim of this work is the establishment of an efficient and accurate digital camera calibration method to be used in particular working conditions, as it can be found with our UAV (Unmanned Aerial Vehicle) photogrammetric projects.

The paper presents how terrestrial laser scanning (TLS) and terrestrial digital photogrammetry were used to create a 3D model of a steep mountain wall. Terrestrial methods of data acquisition are the most suitable for such relief, as the most effective registration is perpendicular to the surface. First, various aspects of photo-based scanning and laser scanning were discussed.

A 3-D imaging technique is presented which pairs high-resolution night-vision cameras with GPS to increase the capabilities of passive imaging surveillance. Camera models and GPS are used to derive a registered point cloud from multiple night-vision images. These point clouds are used to generate 3-D scene models and extract real-world positions of mission critical objects. Analysis shows accuracies rivaling laser scanning even in near-total darkness. The technique has been tested on stereoscopic 3-D video collections as well. Because this technique does not rely on active laser emissions it is more portable, less complex, less costly, and less detectable than laser scanning. This study investigates close-range photogrammetry under night-vision lighting conditions using practical use-case examples of terrain modeling, covert facility surveillance, and stand-off facial recognition.

Investigations of major geological formations are very important since they provide vital information in terms of monitoring of feature changes. This article describes the way in which close range photogrammetry can be used to obtain quantitative information on the geometry and strain patterns in an evolving physical model.

Engineering deformation monitoring requires techniques which can produce high precision and accuracy, reliable measurements at good temporal resolution and fast processing speed. Moreover, monitoring in civil engineering is generally considered to be labour-intensive and financially expensive, and it can take significant effort to arrange the necessary human resources, transportation and equipment maintenance. Such requirements are especially true for monitoring non-rigid membrane structures (defined in this paper as covers or enclosures in which a fabric surface is pre-shaped and pre-tensioned to provide a shape that is stable under environmental loads). Low cost, automated, photogrammetric techniques therefore have the potential to become routinely viable for the structural monitoring of non-rigid membrane structures in the future. This research is investigating the use of close range photogrammetry to be applied at all stages of membrane structure engineering, from materials testing, through dimensional control in construction to in-situ, as-built monitoring of the finished construct.

The main goal of our activity has been the testing of a system for quick and non invasive images acquisition and their suitable processings aimed to obtain 2D & 3D models for archaeological diggings documentation. This purpose has implied the analysis and the selection of a simple and efficient data processing system for the generation of metric products such as digital elevation models and orthophotos, featured by an high level of detail regarding the excavated areas.

Land-based ice cliffs are intriguing features at the margins of glaciers around the world but little is known about mechanisms of their formation and maintenance. The focus of article is on the persistent, rarely-calving ice cliffs on the Kibo glacier, the main peak of Kilimanjaro. Oct 2009 photos were taken covering the sample cliff. PhotoModeler Scanner’s automatic stereo matching lead to a reference digital surface model.

A study was conducted to assess the relative accuracy of two measurement techniques commonly used for vehicle measurements in damaged-based accident reconstruction. The traditional technique of hands-on measurement was compared with the use of photogrammetry for measurement of targeted damaged vehicles. Three undamaged vehicles were subjected to 4 impacts, resulting in 4 damaged areas (two front, one side and one rear).

Ablative heat shields have been used to protect hypersonic vehicles during atmospheric re-entry during the Apollo missions and could be used for future flight vehicles as well. However, it is exceptionally difficult to perform reliable tests at conditions which are representative of flight to validate the models. In this study, the AFIT Mach 3 pressure-vacuum wind tunnel was used in combination with models consisting of dry ice. Measurement was obtained with projected laser dots, high-speed multi-camera photography and PhotoModeler PMV (pre-cursor to PhotoModeler Motion).