One of the biggest problems faced while analyzing digital elevation models (DEMs), particularly DEMs that are produced using photogrammetry, is to avoid pits and peaks in DEMs. Peaks and pits, which are errors, are generated during the surface generation process. DEM smoothening is an important preprocessing step meant for removing these errors. This paper discusses two linear DEM smoothening m...

As one of the important tasks in digital terrain analysis, the calculation of flow accumulations from gridded digital elevation models (DEMs) usually involves two steps in a real application: (1) using an iterative DEM preprocessing algorithm to remove the depressions and flat areas commonly contained in real DEMs, and (2) using a recursive flow-direction algorithm to calculate the flow accumul...

soil salinity has been a large problem in arid and semi arid regions. preparation of such maps is useful for natural resource managers. old methods of preparing such maps require a lot of time and cost. multi-spectral remotely sensed dates due to the broad vision and repeating of these imageries is suitable for provide saline soil maps. this investigation is conducted to provide saline soil map...

The discrete element method (DEM) has been used as a popular simulation method in order to verify the designs by visualizing how materials flow through complex equipment geometries.  Although DEM simulation is a powerful design tool, finding a DEM model that includes all real material properties is not computationally feasible.  In order to obtain more realistic results, particle energy loss du...

Airborne Light Detection and Ranging (LiDAR) topographic data provide highly accurate digital terrain information, which is used widely in applications like creating flood insurance rate maps, forest and tree studies, coastal change mapping, soil and landscape classification, 3D urban modeling, river bank management, agricultural crop studies, etc. In this paper, we focus mainly on the use of L...

Spatial decision support systems (SDSS) are designed to make complex resource allocation problems more transparent and to support the design and evaluation of allocation plans. Recent developments in this field focus on the design of allocation plans using optimization techniques. In this paper we analyze how uncertainty in spatial (input) data propagates through, and affects the results of, an...

The Topographical Survey Division of the Surveys and Mapping Branch, Energy, Mines and Resources, Canada, employs dense digital elevation model (DEM) data for the production of hypsographic overlays for conventional and orthophoto maps. The Gestalt Photomapper (GPM II/3), installed as a production system since summer of 1977, uses computer controlled electronic scanning and image correlation te...

Number: 11 User Lastname: Adam User Firstname: Nico User e-mail: [email protected] Affiliation: German Aerospace CenterGerman Remote Sensing Data Center User Address: German Aerospace CenterGerman Remote Sensing Data CenterOberpfaffenhofen User Telephone: +49 8153 281326 User Fax: +49 8153 281446 Theme: Topographic Mapping and Digital Elevation Models Special Requirements: User Type: Presenter (v...