نتایج جستجو برای: digital elevation model

تعداد نتایج: 2413491  

2014
Carlos A. Felgueiras Jussara de Oliveira Ortiz Eduardo Gerbi Camargo

This short paper describes and analyzes the results of a methodology that allows to conflate existing Digital Elevation Models with a sample set of elevation points in order to obtain more accurate results on modeling elevation information. The set of elevation points has higher vertical accuracy than the DEM and it is used the geostatistical procedure, known as kriging with an external drift, ...

2011
Simon van den Hurk Wallace Yuen Burkhard Wünsche

Real-time terrain rendering techniques usually employ static data structures and do not allow interactive modification of the terrain. In this paper we describe a real-time geometric clipmapping terrain rendering technique for large terrains which allows incremental updates of the underlying data structure. We have combined the method with an interactive sketch-based terrain modelling technique...

Journal: :International Journal of Geographical Information Science 1998
Igor V. Florinsky

We study the accuracy of data on some local topographic attributes derived from digital elevation models (DEMs). First, we carry out a test for the precision of four methods for calculation of partial derivatives of elevations. We ® nd that the Evans method is the most precision algorithm of this kind. Second, we produce formulae for root mean square errors of four local topographic variables (...

1998
Dong-Gyu Sim Rae-Hong Park

This paper proposes the localization algorithm that estimates a ground position by comparing the recovered elevations estimated from aerial images with digital elevation model (DEM). The proposed algorithm consists of two stages: recovering the sampled elevations from multiple aerial images and matching them with DEM. While conventional algorithms estimate the elevation field, that is, recovere...

2009
Irena Hajnsek Kostas Papathanassiou Marc Rodriguez-Cassola

In this paper new and innovative techniques during the commissioning phase of TanDEM-X will be presented that are firstly demonstrated on a satellite platform. The focus is on the secondary goals of TanDEM-X that are assigned for the third year of the mission time life due to the tight schedule for the acquisition of the highly accurate global digital elevation model. Therefore, a variety of sc...

Journal: :Remote Sensing 2016
Laure Roupioz Li Jia Françoise Nerry Massimo Menenti

Considering large and complex areas like the Tibetan Plateau, an analysis of the spatial distribution of the solar radiative budget over time not only requires the use of satellite remote sensing data, but also of an algorithm that accounts for strong variations of topography. Therefore, this research aims at developing a method to produce time series of solar radiative fluxes at high temporal ...

2017
Wenxin Ning Jing Tang Helena L. Filipsson

We analysed the long-term variations in grain-size distribution in sediments from Gåsfjärden, a fjordlike inlet in the southwestern Baltic Sea, and explored potential drivers of the recorded changes in the sediment grain-size data. Over the last 5.4 thousand years (ky) in the study region, the relative sea level decreased 17 m, which was caused by isostatic land uplift. As a consequence, Gåsfjä...

2006
Manfred Zink Gerhard Krieger Hauke Fiedler Irena Hajnsek Alberto Moreira Marian Werner

TanDEM-X opens a new era in space borne radar remote sensing. The first bistatic SAR mission, is formed by adding a second, almost identical spacecraft, to TerraSAR-X and flying the two satellites in a closely controlled formation with typical distances between 250 and 500 m. Primary mission objective is the generation of a consistent global digital elevation model with an unprecedented accurac...

Journal: :سنجش از دور و gis ایران 0
فاطمه توکلی راد دانشگاه تهران حسن احمدی دانشگاه تهران علی اکبر نظری سامانی دانشگاه تهران غلامرضا راهی دانشگاه تهران اسماعیل عباسی دانشگاه تهران

gully erosion is one of the most severe types of water erosion that inclusive and global model to represent its development under different environmental circumstances is difficult. moreover, having knowledge about history behaviors of a gully and its advancement requires direct annual monitoring that is not possible in iran conditions because of cost and time. gis and remote sensing with provi...

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