A continuous data set of Greenland Ice Sheet altimeter height from European Remote Sensing satellites (ERS-1 and ERS-2), 1992 to 2003, has been analyzed. An increase of 6.4 +/- 0.2 centimeters per year (cm/year) is found in the vast interior areas above 1500 meters, in contrast to previous reports of high-elevation balance. Below 1500 meters, the elevation-change rate is -2.0 +/- 0.9 cm/year, i...

Satellite laser altimeter elevation profiles from 2003 to 2006 collected over the lower parts of Whillans and Mercer ice streams, West Antarctica, reveal 14 regions of temporally varying elevation, which we interpret as the surface expression of subglacial water movement. Vertical motion and spatial extent of two of the largest regions are confirmed by satellite image differencing. A major, pre...

In this paper we describe a procedure for generating building models from large scale vector maps and laser altimeter data. First the vector map is analyzed. The result is used to mask the elevation data of single buildings and to derive a coarse 3D-description by prismatic models. Afterwards roofs are reconstructed by fitting planar surfaces to obtain a polyhedral model.

Two recent algorithms for estimating zero-upcross wave periods from altimeter data are investigated using data from a buoy in the North East Pacific with a relatively high occurence of swell. Both algorithms performed well in wind seas, with low wave age, but only one – developed using a neural network – was satisfactory when the wave age was high.

This study presents mathematical analysis and numerical modeling for the estimation of measurement errors height over sea surface a precision radar altimeter installed in low altitude flying vehicle. Reflective properties electromagnetic signals from are determined by local backscattering patterns illuminated. The vehicle received echo at output its tracking system is sum three factors: first f...

The ability of lidar technology to provide three-dimensional elevation maps of the terrain, high precision distance to the ground, and approach velocity can enable safe landing of robotic and manned vehicles with a high degree of precision. Currently, NASA is developing novel lidar sensors aimed at needs of future planetary landing missions. These lidar sensors are a 3-Dimensional Imaging Flash...

This dissertation explores the use of an Airborne Laser Scanner (ALS) for various types of aircraft Terrain-Referenced Navigation (TRN) techniques. Using the methods explored, an ALS-based TERRain Aided Inertial Navigator (TERRAIN) was developed, flight tested, and shown capable of providing meter-level positioning accuracy in real-time. The ALS-based TRN techniques discussed are constrained to...

ATLAS OF ANTARCTICA: TOPOGRAPHIC MAPS FROM GEOSTATISTICAL ANALYSIS OF SATELLITE RADAR ALTIMETER DATA / Ute Christina Herzfeld. Berlin: Springer Verlag, 2004. xvi, 364 pp.: 169 illus., CD-ROM; 10.8 7.800. ISBN 3-540-43457-7 (cloth), US$159.00. Available from: Springer, 233 Spring Street, New York, NY 10013 USA. Toll-free tel. 1-800-SPRINGER. E-mail [email protected]. Web http://www.spr...

In this article, two methods for data collection in urban environments are presented. The first method combines multispectral imagery and laser altimeter data in an integrated classification for the extraction of buildings, trees and grass-covered areas. The second approach uses laser data and 2D ground plan information to obtain 3D reconstructions of buildings. q 1999 Elsevier Science B.V. All...