This module is based on the specifications: ISO 19111 – Geographic information – Spatial Referencing by Coordinates and OGC - Implementation Specification: Coordinate Transformation Services and at providing the mechanisms to represent a coordinate that describes a position on or near the Earth's surface and are referenced to a model of the Earth. Coordinates are referenced to a Coordinate Reference System (CRS). A Coordinate Reference System is a Coordinate System (CS) – an abstract mathematical concept without any relationship to a physical object – that is referenced through a Datum to the Earth or some other object such as a vessel.