In this paper we consider the problem of DTM extraction in dense urban areas. To this aim, we need valuable and reliable data in the tiny open areas among buildings, and a suitable algorithm to reconstruct the terrain discarding these same structures. So, we compare first LIDAR and aerial photogrammetry by evaluating the relative accuracy of the three-dimensional reconstructed surface in the sm...

SUMMARY Three Dimensional Building models are excessively used in various applications. Digital Surface Model is the back bone of the 3D building modeling. The automatic DTM generation techniques are not adequate for the built-up areas. The manual 3D digitization of the stereo images is time consuming. Establishing a semi-automatic technique for the 3D building modeling is required. The main go...

This study describes a new method developed to determine the 3D positional displacements of the drainage networks extracted from Digital Elevation Models (DEMs). The proposed method establishes several stages for data preparation. The displacements are derived by means of linestring-based assessment methods, which can be applied in 2D and 3D. Also, we propose the use of several tools (maps, agg...

The WGS84 ellipsoid is tessellated using quadrilaterals of roughly the same size. The tessellation scheme is developed for the purpose of storing, distributing and analysing global as well as local digital terrain models. Compared with DTED, the new grid has a more uniform distribution of cell sizes. This equal area property of the tiles of the grid is an attractive characteristic in geostatist...

A methodology for downscaling solar irradiation from satellite-derived databases is described using R software. Different packages such as raster, parallel, solaR, gstat, sp and rasterVis are considered in this study for improving solar resource estimation in areas with complex topography, in which downscaling is a very useful tool for reducing inherent deviations in satellite-derived irradiati...

This paper introduces a new computationally inexpensive approach to perception and modeling of the environment that allows fusion of sensory range data of various types and fidelities while explicitly taking into account a complete description of uncertainty of the range measurements. This approach makes use of known sensor uncertainty models to create a single 2.5D digital elevation map whose ...

Nowadays, different sensors and processing techniques provide Digital Elevation Models (DEMs) for the same site, which differ significantly with regard to their geometric characteristics and accuracy. Each DEM contains intrinsic errors due to the primary data acquisition technology, the processing chain, and the characteristics of the terrain. DEM fusion aims at overcoming the limitations of di...

The paper introduces the extraction of objects that are higher than their surroundings, like houses, trees, or bridges, by combining the results of a segmentation of a DTM and a texture analysis of the gray image. We propose a new algorithm (called dual rank) to extract the ground in the DTM, which can be seen as an extension of the gray opening. The extraction of trees in the gray image is don...

The successful operation of the WorldView-1 satellite has enabled advanced high-accuracy mapping using high-resolution satellite images, with or without the use of ground control points (GCPs). The stereo capability of the WorldView-1 sensor also provides the opportunity to extract high-resolution digital elevation models (DEMs). This article will examine the effectiveness of automatic DEM extr...

Automatically extracting object models from images is a complex task We describe research in extracting 3 0 models of buildings from aerial images. This work has resulted in several related systems including assisted extraction (minimal manual interaction to guide automatic processing). automatic extraction with limited imagery and limited building models, and automatic extraction with v e v go...