ASTER is a high-spatial resolution, multispectral imaging system flying aboard TERRA, a satellite launched in December 1999 as part of NASA’s Earth Observing System (EOS). An ASTER scene covering 61.5 km x 63 km contains data from 14 spectral bands. An ASTER Digital Elevation Model (DEM) is generated using bands 3N (nadir) and 3B (backward) level 1A images acquired by the Visible Near Infra-red...

A digital representation of a terrain surface is an approximation of reality and is inherently prone to some degree of error and uncertainty. Research in uncertainty analysis has produced a vast range of methods for investigating error and its propagation. However, the complex and varied methods proposed by researchers and academics create ambiguity for the dataset user. In this study, existing...

Digital Elevation Model (DEM) is a kind of method and means describing three-dimension terrain visualization in computer graphics and visualization. However, there are plenty of redundant data in DEM that is described by grid or TIN (triangulated Irregular Network). The main content of this paper is the study about 3D surface simplification in terrain visualization model based on triangulated n...

This paper presents the results of work carried out under the auspices of the joint ISPRS CNES Scientific Assessment Program of DEM generation from SPOT 5 high resolution stereoscopic (HRS) image data. A stereo pair of HRS images of Melbourne, Australia, with a ground sample distance of 5m in the along track direction, and 10m in the across track direction, was used to create digital surface mo...

TAPES-G is a grid-based terrain analysis program that computes slope, aspect, upslope contributing area, profile and plan curvature and several other topographic attributes for each cell of a square-grid digital elevation model (DEM). These topographic attributes can be used to represent key physical processes in a form simple enough to allow modeling at catchment and larger scales. The program...

Synthetic aperture radar interferometry (InSAR) is an important remote sensing technique to retrieve the terrain digital elevation model (DEM)[1][2]. Image coregistration, InSAR interferometric phase estimation (or noise filtering) and interferometric phase unwrapping[3][4][5][6] are three key processing procedures of InSAR. It is well known that the performance of interferometric phase estimat...

The aim of this tutorial is to show how to easily create a Digital Elevation Model (DEM) and orthorectified image from free ASTER satellite imagery. PCI Geomatica OrthoEngine is the software package used to perform the processing. The imagery used in this tutorial is from Southern Scotland, around Loch Doon in the United Kingdom. These web sites provide contextual pictures of the area….

The ASF Science division has released the world's first free end-to-end interferometric digital elevation model (DEM) generation system. This software, which processes from raw signal data through to a map-projected, ground-range 20m DEM, is completely automated. Preliminary comparison with differential gobal positioning system (GPS) indicates that over a 100km swath, horizontal position errors...

A multibit analog-to-digital converter can achieve high resolution with a lower order modulator and lower oversampling ratio than a single-bit design. However, in a multibit modulator, quantization level errors in the internal multibit quantizer can limit the modulator’s signal-to-noise-and-distortion and spurious-free dynamic range. For a CMOS analog-to-digital converter using a flash analog-t...