February 2009 109 continued on page 110 Introduction Elevation data are an important component in the visualization and analysis of geographic information. The creation and display of 3D models representing bare earth, vegetation, and surface structures have become a major focus of light detection and ranging (lidar) remote sensing research in the past few years. Lidar is an active sensor that ...

The presents study was aimed to create new methods for extraction and analysis of land elevation contour lines, automatic extraction of water bodies (river basins and lakes), from the digital elevation models (DEM) of a test area. And extraction of villages which are fell under critical water scarcity regions for agriculture and drinking water with respect to their elevation data and available ...

Most current flow routing algorithms use digital elevation models (DEMs) to construct flow models. In order to successfully use current techniques for flow routing, they flood local minima and then find a way of routing the flow across the flat surfaces. In this paper, we examine an alternative method for computing flow routing on these flooded surfaces that takes into account the original elev...

This case study concerns vertical errors of five different high-resolution digital elevation models (DEMs) originated from light detection and ranging (LiDAR), interferometric SAR (InSAR) and photogrammetric acquisition. The LiDAR DEM derived from last return points was considered as the reference DEM. The aim was to analyse the statistical and spatial distribution of the residuals and their re...

The paper presents results of a comparative study of the vegetation-caused elevation bias of the space shuttle topographic mission data product, both Cand X-band (SRTM.C/X). The SRTM.C/X bands data were compared against a high-resolution digital terrain model. Pixel-based differences in SRTM.X minus SRTM.C were correlated with land cover (‘agriculture’, ‘house’, ‘tree’, ‘water’). Findings of th...

Massive glacier thinning in the Alps during the past 20 years is documented by direct mass balance measurements on nine regularly observed glaciers. How representative this limited sample of glaciers is for the entire Alps, however, remained uncertain. The near-global digital terrain model from the SRTM enables a closer analysis of this question, which is of fundamental importance to assess ove...

Background and Purpose:  Due to the important role of imaging in the diagnosis and treatment plan in orthodontics, CBCT (Cone Beam Computed Tomography) images because of their three-dimensional nature, can minimize the disadvantages of two-dimensional images such as magnification, distortion, or superimposition. The purpose of this study was to evaluate the accuracy of conventional cephalograms...

The Shuttle Radar Topography Mission (SRTM) was flown in February 2000 and collected the first ever high-resolution near-global digital elevation data. The final SRTM data have become widely available at 1 arc-second resolution for the United States and 3 arc-second resolution for other areas. This article reviews the background of the SRTM mission, the data quality characteristics of the SRTM ...

Nowadays the free-access digital elevation models are getting more and more popular. The SRTM and ASTER GDEM databases are the most widespread. However, there are numerous situations and weaknesses we have to take into account during their usage, such as the direction-dependent accuracy and the difference between the digital and the real surfaces. Our goal was to examine these kinds of deficien...