Results 41 to 50 of about 2,359 (214)

The effect of topographic density variations on the geoid and orthometric heights in Hong Kong

Geodesy and Geodynamics
Utilizing the adopted average topographic density of 2670 kg/m3 in the reduction of gravity anomalies introduces errors attributed to topographic density variations, which consequently affect geoid modeling accuracy.
Albertini Nsiah Ababio
doaj   +1 more source

On the topographic bias and density distribution in modelling the geoid and orthometric heights

Journal of Geodetic Science, 2018
It is well known that the success in precise determinations of the gravimetric geoid height (N) and the orthometric height (H) rely on the knowledge of the topographic mass distribution.
Sjöberg Lars E.
doaj   +1 more source

Evaluating two numerical methods for developing a local geoid model and a local digital elevation model for the Red Sea Coast, Egypt

Journal of King Saud University: Engineering Sciences, 2023
Global Navigation Satellite System (GNSS) provides ellipsoidal heights, whereas engineering projects need orthometric heights of points. Thus, to take advantage of GNSS in engineering work, the relation between orthometric and ellipsoid height must be ...
Hamdy M. Ahmed, Elshewy A. Mohamed, Shaheen A. Bahaa   +2 more
doaj   +1 more source

Converting NAD83 GPS heights into NAVD88 elevations with LVGEOID, a hybrid geoid height model for the Long Valley volcanic region, California [PDF]

, 2008
A GPS survey of leveling benchmarks done in Long Valley Caldera in 1999 showed that the application of the National Geodetic Survey (NGS) geoid model GEOID99 to tie GPS heights to historical leveling measurements would significantly underestimate the
BATTAGLIA, MAURIZIO, D. DZURISIN, D. P. HILL, J. LANGBEIN, J. SVARC   +4 more
core  

Improved mapping functions for atmospheric refraction correction in SLR [PDF]

, 2002
[1] We present two new mapping functions (MFs) to model the elevation angle dependence of the atmospheric delay for satellite laser ranging (SLR) data analysis.
Langley, RB, Mendes, VB, Pavlis, DE, Pavlis, EC, Prates, Gonçalo   +4 more
core   +1 more source

High‐Resolution Digital Terrain Model and Land‐Surface Parameters of São Sebastião and Ilhabela, Southeastern Brazil

Geoscience Data Journal, Volume 13, Issue 2, April 2026.
The first openly accessible 2 m‐resolution lidar‐based DTM and an extensive set of land‐surface parameters (LSPs) for the region of São Sebastião and Ilhabela, southeastern Brazil, reveal geomorphological features previously indiscernible, including past landslide deposits, drainage captures and structural lineaments.
Rebeca Durço Coelho, Gabriella Labate Frugis, Camila Duelis Viana, Carlos Henrique Grohmann   +3 more
wiley   +1 more source

A MATLAB GEODETIC SOFTWARE FOR PROCESSING AIRBORNE LIDAR BATHYMETRY DATA [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015
The ability to build three-dimensional models through technologies based on satellite navigation systems GNSS and the continuous development of new sensors, as Airborne Laser Scanning Hydrography (ALH), data acquisition methods and 3D multi-resolution ...
M. Pepe, G. Prezioso
doaj   +1 more source

Height determination using GPS data, local geoid and global geopotential models [PDF]

, 1995
Orthometric heights are normally derived using the spirit levelling. This requires the spirit level equipment to be set up from point 10 point along a levelling line which is a time consuming and tedious task.
Abdullah, Khairul Anuar
core  

Evaluating SWOT in the Coastal Zone: Comparisons With Tide Gauge and Airborne LiDAR in the Bristol Channel and Severn Estuary, UK

Geophysical Research Letters, Volume 53, Issue 2, 28 January 2026.
Abstract Traditional nadir altimeters struggle with coastal water surface elevation (WSE) measurement and fine‐scale river‐estuary interactions, due to land‐water signal interference and their wide inter‐track spacing. The wide‐swath Surface Water and Ocean Topography (SWOT) mission, using a new Ka‐band radar interferometer, aims to address these ...
Youtong Rong, Paul Bates, Jeff Neal, Paul Bell, Christine Gommenginger, Ian Dougal Lichtman, Christopher Banks, Francisco J. M. Calafat, Adrien Martin, Jennifer Brown, Richard Cooke, Christopher Balfour, Michela De Dominicis, Marta Payo Payo, Simon Williams, Laurent Amoudry, Stephen Chuter, Simon Neill, Jude Chisholm, Colin J. Gleason, John Kupiec, Matt Lewis   +21 more
wiley   +1 more source

Improving Geoidal Height Estimates from Global Geopotential Model Using Regression Model and GPS Data [PDF]

, 1997
Conventionally, for most application, position of a point is often referred to the geoid as the reference surface. Thus there is an important need for the knowledge of the geoid undulation in the area where positioning tasks is performed, This ...
Abdullah, Khairul Anuar
core