In the same area, the terrain details described by DEM are gradually generalized and primary terrain features are only retained in the coarser-resolution DEM. In this paper, wavelet multiresolution analysis and Radical Law selection principles were combined to model the terrain generalizing processes and derive three different scale-parameter DEMs based on DEM data generated by large-scale digi...

This paper describes a new fast and scalable parallel algorithm to compute global flow accumulation for automatic drainage network extraction in large digital elevation models (DEM for short). Our method uses the D8 model to compute the flow directions for all pixels in the DEM (except NODATA and oceans). A parallel spanning tree algorithm is proposed to compute hierarchical catchment basins to...

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...

An accurate digital elevation model (DEM) is a critical data set for characterizing the natural landscape, monitoring natural hazards, and georeferencing satellite imagery. The ideal interferometric synthetic aperture radar (InSAR) configuration for DEM production is a single-pass two-antenna system. Repeat-pass single-antenna satellite InSAR imagery, however, also can be used to produce useful...

Partial randomization dynamic element matching (DEM) was recently introduced as a promising DEM technique for low harmonic distortion digital-to-analog conversion. The DEM technique is well suited for applications such as direct digital synthesis in wireless communication systems for which low hardware complexity is essential in addition to low harmonic distortion. Previously reported simulatio...

One of the most widely available procedures packaged with CIS for the analysis of a Digital Elevation Model (DEM) is the identification of the viewable area, or the viewshed. The elevations recorded in the DEM do, however, contain error, and the USGS, for example, publishes a Root Mean Squared Error (RMSE) for each DEM. Research reported here assesses the uncertainty of locations being within a...

Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Abstract Digital elevation models (DEMs) represent the topography that drives s...

SUMMARY As part of ISO standards on public-key encryption, Shoup introduced the framework of KEM (Key Encapsulation Mechanism), and DEM (Data Encapsulation Mechanism), for formalizing and realizing one-directional hybrid encryption; KEM is a formalization of asymmetric en-cryption specified for key distribution, which DEM is a formalization of symmetric encryption. This paper investigates a mor...