Interface CoordinateReferenceSystem

All Superinterfaces:
IdentifiedObject, ReferenceSystem
All Known Subinterfaces:
CompoundCRS, DerivedCRS, EngineeringCRS, GeneralDerivedCRS, GeocentricCRS, GeodeticCRS, GeographicCRS, ImageCRS, ParametricCRS, ProjectedCRS, SingleCRS, TemporalCRS, VerticalCRS

Base type of all Coordinate Reference Systems (CRS). This is the base interface for two cases:


A coordinate reference system (CRS) captures the choice of values for the parameters that constitute the degrees of freedom of the coordinate space. The fact that such a choice has to be made, either arbitrarily or by adopting values from survey measurements, leads to the large number of coordinate reference systems in use around the world. It is also the cause of the little understood fact that the latitude and longitude of a point are not unique. Without the full specification of the coordinate reference system, coordinates are ambiguous at best and meaningless at worst.

Spatiotemporal CRS

The concept of coordinates may be expanded from a strictly spatial context to include time. Time is then added as another coordinate to the coordinate tuple. It is even possible to add two time-coordinates, provided the two coordinates describe different independent quantities. An example of the latter is the time/space position of a subsurface point of which the vertical coordinate is expressed as the two-way travel time of a sound signal in milliseconds, as is common in seismic imaging. A second time-coordinate indicates the time of observation.