# Wolfram Language & System 10.0 (2014)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.
BUILT-IN WOLFRAM LANGUAGE SYMBOL

# GeoGridPosition

GeoGridPosition[{x,y},proj]
represents a point in a planimetric cartographic grid using the projection proj.

GeoGridPosition[{x,y,h},proj]
represents a point in a cartographic grid with height h with respect to the reference ellipsoid.

GeoGridPosition[{x,y,h},proj,datum]
represents a point in a cartographic grid obtained by projection from data in the given datum.

## DetailsDetails

• GeoGridPosition[pos,projection] converts from any geographic position to a grid point, essentially computing a cartographic projection. Any of the following coordinate types can be given: GeoPosition, GeoPositionXYZ, GeoPositionENU, GeoGridPosition.
• GeoGridPosition[GeoPosition[{ϕ,λ}],proj] performs the direct projection from geodetic coordinates to the projected map.
• Conversely, GeoPosition[GeoGridPosition[{x,y},proj]] performs the inverse projection from the map to geodetic coordinates.
• Projections can be specified in the following forms:
•  "proj" named projection with default parameter values {"proj","param1"->val1,"param2"->val2,…} projection with detailed parameters specified
• Names of possible projections are given by .
• Default values of parameters for a particular named projection are given by GeoProjectionData[proj].
• GeoGridPosition[{x,y},proj] represents a point in a cartographic grid, assuming a standard ellipsoid height of zero.
• GeoGridPosition[{x,y,h,t},proj] includes a time t measured in seconds since the beginning of January 1, 1900 in the GMT time zone.
• Values of height h and time t are preserved in the projection.

## ExamplesExamplesopen allclose all

### Basic Examples  (3)Basic Examples  (3)

Convert a geodetic position to a grid point using a spherical Bonne projection:

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Convert back to a geodetic position:

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Compute a spherical gnomonic projection using a custom setting for the central meridian:

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Compute a projection using explicitly specified projection parameters:

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