Projection Type

Represents a 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.

WKT specifications must follow the WKT standard syntax. See the example below:

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 Proj4 specification syntax. Example:

[ +proj=latlong +ellps=GRS80 +towgs84=-199.87,74.79,246.62 ]

GUI Editor

EGO Script

A constant representing a projection in a EGO Script can be defined in two different ways:

Using ERMapper parameters

[| "COORDINATE_TYPE", "ERMAPPER_PROJECTION", "ERMAPPER_DATUM", "ERMAPPER_UNIT" |]

All parameters are case-insensitive and must be surrounded by double quotes.

Example:

[| "LATLONG", "GEODETIC", "WGS84", "METERS" |]

Using a WKT (Well-Known Text) description

[| "COORDINATE_TYPE", WKT_PROJECTION |]

The syntax used to the represent the WKT_PROJECTION can be found here.

It is worth nothing that only the COORDINATE_TYPE must be surrounded by double quotes.

Example:

[| "LATLONG", PROJCS["unnamed", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]], TOWGS84[0,0,0,0,0,0,0], AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9108"]], AUTHORITY["EPSG","4326"]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",90], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",500000], PARAMETER["false_northing",-2000000], UNIT["METERS",1]]] |]

Using a Proj4 description

[| "COORDINATE_TYPE", [ PROJ4_PROJECTION ] |]

The syntax used to the represent the PROJ4_PROJECTION can be found here.

Example:

[| "LATLONG", [ +proj=longlat +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +no_defs ] |]

Using a EPSG code

[| "COORDINATE_TYPE", EPSG_CODE ] |]

Example:

[| "LATLONG", 7030 |]

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.