نتایج جستجو برای: digital elevation model dem

تعداد نتایج: 2428615  

2007
Addy POPE Tavi MURRAY Adrian LUCKMAN

Photogrammetric digital elevation models (DEMs) are often used to derive and monitor surfaces in inaccessible areas. They have been used to monitor the spatial and temporal change of glacier surfaces in order to assess glacier response to climate change. However, deriving photogrammetric DEMs of steep mountainous topography where the surface is often obscured by regions of deep shadow and snow ...

Journal: :JCP 2014
Li-fu Chen Hongguang Xiao Hai-Liang Wang Yueguan Lin

The technique of Interferometric Synthetic Aperture Radar can generate high precise Digital Elevation Model (DEM) fast, which makes it play a very important role in the development of social economy and construct of national defense. Once the high precise DEM can be acquired in real-time, the worthiness of the technique will be embodied fully. In this thesis, the research dynamic of generating ...

2015
Manfred Zink Alberto Moreira

TanDEM-X is a challenging radar mission. It consists of a synthetic aperture radar interferometer with two almost identical satellites flying in a closely controlled formation. With a typical separation between the satellites of 120 to 500 m a global Digital Elevation Model (DEM) with 2 m relative height accuracy at 12 m posting is being generated. While the main mission phase for DEM data acqu...

2002
Ulrich Kamp

Digital elevation models (DEMs) are increasingly used for visual and mathematical analysis of topography, landscapes and landforms, as well as modeling of surface processes. A DEM of Cerro Sillajhuay, a volcano in the Andes of Chile/Bolivia, was developed from ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite data. The original 30-m DEM was generated by using tie ...

2007
Masato Furuya

The Interferometric Point Target Analysis (IPTA) technique was applied to Izu-Oshima volcano, Japan, using both JERS SAR data from 1992 to 1998 and a 50-meter mesh digital elevation model (DEM) measured in 1981. The caldera region showed significant extension in the radar line-of-sight (LOS) at a maximum rate of 4 cm/yr around the 1986 eruption vent. Also, the DEM turns out be corrected by 10-3...

Journal: :Remote Sensing 2015
Yanjun Su Qinghua Guo Qin Ma Wenkai Li

The Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) is one of the most complete and frequently used global-scale DEM products in various applications. However, previous studies have shown that the SRTM DEM is systematically higher than the actual land surface in vegetated mountain areas. The objective of this study is to propose a procedure to calibrate the SRTM DEM over l...

2014
G. Scarmana

At present, computers, lasers, radars, planes and satellite technologies make possible very fast and accurate topographic data acquisition for the production of maps. However, the problem of managing and manipulating this data efficiently remains. One particular type of map is the elevation map. When stored on a computer, it is often referred to as a Digital Elevation Model (DEM). A DEM is usua...

2015
Christopher Wecklich Carolina Gonzalez Benjamin Bräutigam

The TanDEM-X system is an innovative radar mission, which is comprised of two formation flying satellites, with the primary goal of generating a global Digital Elevation Model (DEM) of unprecedented accuracy. TanDEM-X, being a large single-pass radar interferometer, achieves this accuracy through a flexible baseline selection enabling the acquisition of highly accurate cross-track interferogram...

Journal: :محیط شناسی 0
مهندس محسن محفوظی دکتر مجید مخدوم دکتر علی اصغر درویش صفت

in order to determine optimum landuses (in accordance with natural capability) and improve the current land management, landuse planning process was applied by using gis. within the framework of system analysis approach basic ecological and socio-economic , data were mapped. the mapped data were digitized and imported to idrisi and arc/info to build a database ,along with other descriptive data...

Journal: :Ground water 2009
Eve L Kuniansky Mark A Lowery Bruce G Campbell

For regional models, the shallow water table surface is often used as a source/sink boundary condition, as model grid scale precludes simulation of the water table aquifer. This approach is appropriate when the water table surface is relatively stationary. Since water table surface maps are not readily available, the elevation of the water table used in model cells is estimated via a two-step p...

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