.. index:: single: crs_projections .. _crs_projections/0:

.. rst-class:: right

object

crs_projections

Coordinate reference systems and common transformations for 2D and 3D WGS84 geodetic coordinates, Web Mercator, World Mercator, ECEF, local ENU tangent-plane, Lambert azimuthal equal-area, and UTM coordinates.

| Availability: | logtalk_load(crs_projections(loader))

| Author: Paulo Moura | Version: 1:0:0 | Date: 2026-05-10

| Compilation flags: | static, context_switching_calls

| Implements: | public :ref:`crs_projections_protocol <crs_projections_protocol/0>` | Uses: | :ref:`geospatial <geospatial/0>`

| Remarks:

• Geographic coordinates: WGS84 coordinates are represented as geographic(Latitude,Longitude) in degrees.
• 3D geodetic coordinates: WGS84 3D coordinates are represented as geographic(Latitude,Longitude,EllipsoidalHeight) using degrees for angular axes and meters for height.
• Projected coordinates: Web Mercator, World Mercator, and Lambert azimuthal equal-area coordinates are represented as meter-based projected(X,Y) pairs. UTM coordinates are represented as grid(Easting,Northing) pairs.
• Geocentric coordinates: ECEF coordinates are represented as ecef(X,Y,Z) triples in meters.
• Local tangent-plane coordinates: ENU coordinates are represented as enu(East,North,Up) triples in meters relative to an origin coordinate.
• UTM coverage: UTM helpers and transformations only succeed for latitudes in the [-80.0,84.0[ range.

| Inherited public predicates: |  :ref:`crs_projections_protocol/0::crs_dimensions/2`  :ref:`crs_projections_protocol/0::crs_epsg/2`  :ref:`crs_projections_protocol/0::crs_kind/2`  :ref:`crs_projections_protocol/0::crs_name/2`  :ref:`crs_projections_protocol/0::crs_units/2`  :ref:`crs_projections_protocol/0::epsg_crs/2`  :ref:`crs_projections_protocol/0::lambert_azimuthal_equal_area/3`  :ref:`crs_projections_protocol/0::lambert_azimuthal_equal_area_inverse/3`  :ref:`crs_projections_protocol/0::local_tangent_plane/3`  :ref:`crs_projections_protocol/0::local_tangent_plane_inverse/3`  :ref:`crs_projections_protocol/0::transform/4`  :ref:`crs_projections_protocol/0::utm_crs/2`  :ref:`crs_projections_protocol/0::utm_zone/2`  :ref:`crs_projections_protocol/0::valid_coordinate/2`  :ref:`crs_projections_protocol/0::valid_crs/1`  

.. contents:: :local: :backlinks: top

Public predicates

(no local declarations; see entity ancestors if any)

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

(no local declarations; see entity ancestors if any)

Operators

(none)

.. seealso::

:ref:`crs_projections_protocol <crs_projections_protocol/0>`, :ref:`geospatial <geospatial/0>`