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projection_type [2013/08/08 03:24] admin [Projection Type] |
projection_type [2016/11/22 22:00] hermann [Projection Type] |
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====== Projection Type ====== | ====== Projection Type ====== | ||
- | Represents a [[wp>Map_projection|map projection]]. | + | Represents a [[wp>Map_projection|map projection]]. Projections can be defined using the predefined options (UTM, Geodetic etc), using a WKT specification, using an EPSG code or using a Proj4 specification. |
- | ===== Automatic Conversions ===== | + | WKT specifications must follow the [[wkt format|WKT standard syntax]]. See the example below: |
- | * **Converted from**: [[Map Type]] and [[Categorical Map Type]]. | + | PROJCS["SUTM21", |
+ | GEOGCS["SOUTH AMERICAN 1969", | ||
+ | DATUM["SAD69", | ||
+ | SPHEROID["INT67",6378160,298.25]], | ||
+ | PRIMEM["Greenwich",0], | ||
+ | UNIT["degree",0.0174532925199433]], | ||
+ | PROJECTION["Transverse_Mercator"], | ||
+ | PARAMETER["latitude_of_origin",0], | ||
+ | PARAMETER["central_meridian",-57], | ||
+ | PARAMETER["scale_factor",0.9996], | ||
+ | PARAMETER["false_easting",500000], | ||
+ | PARAMETER["false_northing",10000000], | ||
+ | UNIT["Meter",1]] | ||
+ | |||
+ | The Proj4 syntax must also follow the [[http://proj4.org/parameters.html|Proj4 specification syntax]]. Example: | ||
+ | |||
+ | [ +proj=latlong +ellps=GRS80 +towgs84=-199.87,74.79,246.62 ] | ||
- | * **Converted to**: None. | ||
===== GUI Editor ===== | ===== GUI Editor ===== | ||
- | [{{ :editors:projection_editor.png?nolink& |Graphical representation of the projection editor}}] | + | [{{ :editors:projection_editor.png?nolink&500 |Graphical representation of the projection editor}}] |
===== EGO Script ===== | ===== EGO Script ===== | ||
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[| "LATLONG", "GEODETIC", "WGS84", "METERS" |] | [| "LATLONG", "GEODETIC", "WGS84", "METERS" |] | ||
</code> | </code> | ||
+ | |||
==== Using a WKT (Well-Known Text) description ==== | ==== Using a WKT (Well-Known Text) description ==== | ||
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PARAMETER["false_northing",-2000000], | PARAMETER["false_northing",-2000000], | ||
UNIT["METERS",1]]] | UNIT["METERS",1]]] | ||
+ | |] | ||
+ | </code> | ||
+ | |||
+ | ==== Using a Proj4 description ==== | ||
+ | |||
+ | <code cpp> | ||
+ | [| "COORDINATE_TYPE", [ PROJ4_PROJECTION ] |] | ||
+ | </code> | ||
+ | |||
+ | The syntax used to the represent the PROJ4_PROJECTION can be found [[http://proj4.org/parameters.html|here]]. | ||
+ | |||
+ | Example: | ||
+ | <code cpp> | ||
+ | [| "LATLONG", | ||
+ | [ +proj=longlat +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +no_defs ] | ||
+ | |] | ||
+ | </code> | ||
+ | |||
+ | ==== Using a EPSG code ==== | ||
+ | |||
+ | <code cpp> | ||
+ | [| "COORDINATE_TYPE", EPSG_CODE ] |] | ||
+ | </code> | ||
+ | |||
+ | Example: | ||
+ | <code cpp> | ||
+ | [| "LATLONG", | ||
+ | 7030 | ||
|] | |] | ||
</code> | </code> | ||
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---- | ---- | ||
A COORDINATE_TYPE is also case-insensitive and must be represented using keywords "en" (Easting/Northing), "latlong" (Latitude/Longitude) and "none". The latter can be used to automatically derive the coordinate type based on the projection parameters. | A COORDINATE_TYPE is also case-insensitive and must be represented using keywords "en" (Easting/Northing), "latlong" (Latitude/Longitude) and "none". The latter can be used to automatically derive the coordinate type based on the projection parameters. | ||
+ | |||
+ | ===== Automatic Conversions ===== | ||
+ | |||
+ | * **Converted from**: [[Map Type]] and [[Categorical Map Type]]. | ||
+ | |||
+ | * **Converted to**: None. | ||