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Diffstat (limited to 'us_nga')
| l--------- | us_nga/.github/README.md | 1 | ||||
| -rw-r--r-- | us_nga/README.us_nga | 30 |
2 files changed, 31 insertions, 0 deletions
diff --git a/us_nga/.github/README.md b/us_nga/.github/README.md new file mode 120000 index 0000000..a728266 --- /dev/null +++ b/us_nga/.github/README.md @@ -0,0 +1 @@ +../README.us_nga
\ No newline at end of file diff --git a/us_nga/README.us_nga b/us_nga/README.us_nga new file mode 100644 index 0000000..5050916 --- /dev/null +++ b/us_nga/README.us_nga @@ -0,0 +1,30 @@ +# README.us_nga + +The files in this section result from the conversion of datasets originating +from [US NGA](http://earth-info.nga.mil) + +## Included grids + +### Worldwide: EGM96 geoid model + +*Source*: [NGA](http://earth-info.nga.mil/GandG/wgs84/gravitymod/egm96/egm96.html) +*Format*: GeoTIFF converted from GTX +*License*: Public Domain + +15 minute worldwide geoid undulation grid that transforms physical heights to WGS84 ellipsoidal heights. + +* egm96_15.tif + +### Vertical grid: EGM2008 geoid model + +*Source*: [NGA](http://earth-info.nga.mil/GandG/wgs84/gravitymod/egm2008/egm08_wgs84.html) +*Format*: GeoTIFF converted from GTX +*License*: Public Domain + +2.5 minute worldwide geoid undulation grid that transforms physical heights to WGS84 ellipsoidal heights. + +This file has been produced by [GeographicLib](https://geographiclib.sourceforge.io/html/gravity.html) +using the EGM2008 gravity model and can be regenerated with the +[build_egm08_25_gtx.sh](https://raw.githubusercontent.com/OSGeo/proj-datumgrid/master/world/build_egm08_25_gtx.sh) script. + +* egm08_25.tif |