Questions tagged [egm96]

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4 votes
2 answers
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Convert Vertical Datum of GDAL file

I have 2 DTM datasets, the first has a vertical datum of WGS84, while the second has an orthometric vertical datum (maybe EGM96). gdalinfo seems to only provide the horizontal datum info: Size is ...
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NAVD88 not in Vertical Reference drop down list of Drone2Map

I use the Propeller company's Aeropoint GPS tiles to collect ground control for drone flights. When trying to import my ground control points, the survey report provides the coordinate reference ...
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1 answer
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How to get the EGM96 and EGM2008 elevations of a list of WGS84 lat/lng coordinates from a file using GDAL?

I'm trying to do the following: Given a list of WGS84 latitude / longitude pairs in a text file (one pair per line), I'd like to compute the EGM96 and EGM2008 elevations corresponding to those points ...
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  • 131
2 votes
0 answers
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What's this 8 byte "padding" in the EGM2008 data?

I recently downloaded the 1' earth gravitational model 2008 Und_min1x1_egm2008_isw=82_WGS84_TideFree dataset from here. According to the readme, the file consists of 233,301,600 32-bit floating point ...
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0 votes
1 answer
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Are WGS84 LatLon coordinates and EGM96 LatLon coordinates the same and difference for [LatLonEle] is elevation only?

Does WGS84 LatLon coordinates and EGM96 LatLon coordinates are the same? Is difference for [Lat;Lon;Ele] is in elevation only? If I have, for example, a [Lat;Lon] point in WGS84, I can take ...
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  • 133
7 votes
4 answers
1k views

How does a Spatial Reference System like WGS84 have an elipsoid and a geoid?

I found out that WGS84 is an ellipsoid with a "geoid component", but I'm unsure exactly how that can be. This is from PostGIS in Action, Second Edition (pg. 64), but it seemed a bit vague. ...
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6 votes
3 answers
442 views

Vertical datum query for coastal modeling

I have a USGS derived DEM with a vertical datum of EGM96 from NASA satellite data. My Bathymetry uses a lowest astronomical tide datum. Has anybody come across this or similar issue before? I need ...
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  • 191
13 votes
2 answers
31k views

How are EGM96 and WGS84 related to each other?

As far as I understand the EGM96 defines the Geoid, where as the WGS84 Standard defines the Ellipsoid. Is the ellipsoid defined in the WGS84 standard defined in a way to maximize the congruency with ...
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