> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wherobots.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Geography Functions

The `Geography` type in Sedona represents spatial objects on a spherical (geodesic) model of the Earth. Unlike the planar [Geometry](/reference/wherobots-db/geometry-data/geometry-functions) type, distance, area, and other measurements performed on `Geography` objects account for the curvature of the Earth and return results in real-world units (e.g., meters).

## Geography Constructors

These functions create geography objects from various formats.

| Function                                                                                               | Return type | Description                                                                                                                                                                                              |
| :----------------------------------------------------------------------------------------------------- | :---------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [ST\_GeogFromEWKB](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogFromEWKB)       | Geography   | Construct a Geography from EWKB Binary. This function is an alias of [ST\_GeogFromWKB](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogFromWKB).                                     |
| [ST\_GeogFromEWKT](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogFromEWKT)       | Geography   | Construct a Geography from OGC Extended WKT.                                                                                                                                                             |
| [ST\_GeogFromGeoHash](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogFromGeoHash) | Geography   | Create Geography from geohash string and optional precision                                                                                                                                              |
| [ST\_GeogFromWKB](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogFromWKB)         | Geography   | Construct a Geography from WKB Binary.                                                                                                                                                                   |
| [ST\_GeogFromWKT](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogFromWKT)         | Geography   | Construct a Geography from WKT. If SRID is not set, it defaults to 0 (unknown).                                                                                                                          |
| [ST\_GeogToGeometry](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeogToGeometry)   | Geometry    | This function constructs a planar Geometry object from a Geography. While Sedona makes every effort to preserve the original spatial object, the conversion is not always exact because Geography and... |
| [ST\_GeomToGeography](/reference/wherobots-db/geometry-data/geography/constructors/ST_GeomToGeography) | Geography   | This function constructs a Geography object from a planar Geometry. This function is intended for geometries defined in a Geographic Coordinate Reference System (CRS), most commonly WGS84 (EPSG:432... |

## Geography Functions

These functions operate on geography type objects.

| Function                                                                              | Return type | Description                                                                                                                                                                                              |
| :------------------------------------------------------------------------------------ | :---------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [ST\_AsEWKT](/reference/wherobots-db/geometry-data/geography/functions/ST_AsEWKT)     | String      | Return the Extended Well-Known Text representation of a geography. EWKT is an extended version of WKT which includes the SRID of the geography. The format originated in PostGIS but is supported by ... |
| [ST\_Envelope](/reference/wherobots-db/geometry-data/geography/functions/ST_Envelope) | Geography   | This function returns the bounding box (envelope) of A. It's important to note that the bounding box is calculated using a cylindrical topology, not a spherical one. If the envelope crosses the ant... |