Microcomputer Application of Digital Elevation Models and Other Gridded Data Sets for Geologists

The aim of this study was to compare the hydrographically conditioned digital elevation models (HCDEMs) generated from data of VNIR (Visible Near Infrared) sensor of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), of SRTM (Shuttle Radar Topography Mission) and topographical maps from IBGE in a scale of 1:50,000, processed in the Geographical Information System (GIS), aiming the morphometric characterization of watersheds. It was taken as basis the Sub-basin of São Bartolomeu River, obtaining morphometric characteristics from HCDEMs. Root Mean Square Error (RMSE) and cross validation were the statistics indexes used to evaluate the quality of HCDEMs. The percentage differences in the morphometric parameters obtained from these three different data sets were less than 10%, except for the mean slope (21%). In general, it was observed a good agreement between HCDEMs generated from remote sensing data and IBGE maps. The result of HCDEM ASTER was slightly higher than that from HCDEM SRTM. The HCDEM ASTER was more accurate than the HCDEM SRTM in basins with high altitudes and rugged terrain, by presenting frequency altimetry nearest to HCDEM IBGE, considered standard in this study.

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Validation of satellite altimetry by kinematic GNSS in central East Antarctica

The Cryosphere ◽

10.5194/tc-11-1111-2017 ◽

2017 ◽

Vol 11 (3) ◽

pp. 1111-1130 ◽

Cited By ~ 16

Author(s):

Ludwig Schröder ◽

Andreas Richter ◽

Denis V. Fedorov ◽

Lutz Eberlein ◽

Evgeny V. Brovkov ◽

...

Keyword(s):

Satellite Altimetry ◽

Digital Elevation Models ◽

Surface Elevation ◽

Data Sets ◽

Radar Altimetry ◽

Independent Evidence ◽

Ice Surface ◽

Digital Elevation ◽

Wide Range ◽

Elevation Data

Abstract. Ice-surface elevation profiles of more than 30 000 km in total length are derived from kinematic GNSS (GPS and the Russian GLONASS) observations on sledge convoy vehicles along traverses between Vostok Station and the East Antarctic coast. These profiles have accuracies between 4 and 9 cm. They are used to validate elevation data sets from both radar and laser satellite altimetry as well as four digital elevation models. A crossover analysis with three different processing versions of Envisat radar altimetry elevation profiles yields a clear preference for the relocation method over the direct method of slope correction and for threshold retrackers over functional fit algorithms. The validation of CryoSat-2 low-resolution mode and SARIn mode data sets documents the progress made from baseline B to C elevation products. ICESat laser altimetry data are demonstrated to be accurate to a few decimetres over a wide range of surface slopes. A crossover adjustment in the region of subglacial Lake Vostok combining ICESat elevation data with our GNSS profiles yields a new set of ICESat laser campaign biases and provides new, independent evidence for the stability of the ice-surface elevation above the lake. The evaluation of the digital elevation models reveals the benefits of combining laser and radar altimetry.

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Glacier mapping: a review with special reference to the Indian Himalayas

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133309348112 ◽

2009 ◽

Vol 33 (5) ◽

pp. 672-704 ◽

Cited By ~ 122

Author(s):

Rakesh Bhambri ◽

Tobias Bolch

Keyword(s):

Nineteenth Century ◽

Special Reference ◽

Digital Elevation Models ◽

Geological Survey ◽

Data Sets ◽

Volume Changes ◽

Glacier Fluctuations ◽

Digital Elevation ◽

Glacier Mapping ◽

Indian Himalayas

This paper deals with the development of glacier mapping and glacier fluctuations since the mid-nineteenth century, with special reference to the Indian Himalayas, and the contributions of the Survey of India and the Geological Survey of India. In addition, it presents a review of the limitations and challenges relating to: the mapping of clean-ice and debris-covered glaciers; the comparison of different data sets; and the measurement of glacier volume changes based on multitemporal digital elevation models. Possible solutions are discussed, and the emerging areas of glacier mapping research and applications for the Indian Himalayas are highlighted.

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Beach Morphology and Sediment Budget Variability Based on High Quality Digital Elevation Models Derived from Field Data Sets

International Journal of Geosciences ◽

10.4236/ijg.2011.22012 ◽

2011 ◽

Vol 02 (02) ◽

pp. 111-119 ◽

Cited By ~ 6

Author(s):

Mohammed Taaouati ◽

El Mrini Abdelmounim ◽

Driss Nachite

Keyword(s):

Field Data ◽

Digital Elevation Models ◽

Sediment Budget ◽

Data Sets ◽

High Quality ◽

Beach Morphology ◽

Digital Elevation

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EVALUATING DIFFERENT WATER-LAND-BOUNDARY APPROXIMATIONS TO IMPROVE SAR-DERIVED DIGITAL ELEVATION MODELS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b1-2021-51-2021 ◽

2021 ◽

Vol XLIII-B1-2021 ◽

pp. 51-56

Author(s):

B. Schneider ◽

E. Wortmeyer ◽

S. Schmitz ◽

A. Thiele ◽

P. Havel ◽

...

Keyword(s):

Wadden Sea ◽

Environmental Changes ◽

Digital Elevation Models ◽

Remote Sensing Data ◽

Data Sets ◽

Data Set ◽

Digital Elevation ◽

Sar Data ◽

Airborne Sar ◽

Water Saturated

Abstract. The coastline of the German Wadden Sea is constantly subjected to the tides and the tidal-induced environmental changes like erosion and accumulation of sediments need to be monitored constantly. This task requires digital elevation models (DEMs), which are derived from remote sensing data. To model those DEMs, a separation of data collected over landmasses and water bodies is required. In the GeoWAM project the potential of airborne SAR-data (F-SAR) is investigated for monitoring purposes in the Wadden Sea. As part of the project, this paper focuses on the suitability of F-SAR data regarding the derivation of water-land-boundaries (WLBs). Therefore, water-land-boundaries based on independent data sets are compared and evaluated. Analyzed data sets include data collected via F-SAR, airborne laserscanning (ALS), on site GNSS measured WLB points and sea-level data from two acoustic gauges. The algorithms were tested on a study site on Spiekeroog island. Our results show, that the accuracies of the derived WLBs mostly depend on the on-site topography and sediments. The spatial deviation between the reference data and the approximated WLBs is mostly less than 2 m horizontally and 0.15 m vertically. Identified challenges to overcome are mostly related to processing of F-SAR data in areas with highly water saturated sediments. Our results suggest, that F-SAR data in tidal flats is not necessarily dependent on further supplementing surveys, as one of the main advantages of the F-SAR data is the potential to derive DEMs and WLBs from the same data set.

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