## Uses of Class
org.apache.sis.referencing.AbstractReferenceSystem

- Packages that use AbstractReferenceSystem
  Package | Description
  --- | ---
  org.apache.sis.referencing.crs | Coordinate Reference System (CRS) definitions as coordinate systems related to the earth through datum.
  org.apache.sis.referencing.gazetteer | Mapping between geographic identifiers (addresses, grid indexes…) and locations (descriptions, coordinates…).

- - ### Uses of AbstractReferenceSystem in org.apache.sis.referencing.crs

    Subclasses of AbstractReferenceSystem in org.apache.sis.referencing.crs
    Modifier and Type | Class | Description
    --- | --- | ---
    `class` | `AbstractCRS` | Coordinate reference system, defined by a coordinate system and (usually) a datum.
    `class` | `DefaultCompoundCRS` | A CRS describing the position of points through two or more independent coordinate reference systems.
    `class` | `DefaultDerivedCRS` | A coordinate reference system that is defined by its coordinate conversion from another CRS (not by a datum).
    `class` | `DefaultEngineeringCRS` | A 1-, 2- or 3-dimensional contextually local coordinate reference system.
    `class` | `DefaultGeocentricCRS` | A 3-dimensional coordinate reference system with the origin at the approximate centre of mass of the earth.
    `class` | `DefaultGeographicCRS` | A 2- or 3-dimensional coordinate reference system based on an ellipsoidal approximation of the geoid.
    `class` | `DefaultImageCRS` | A 2-dimensional engineering coordinate reference system applied to locations in images.
    `class` | `DefaultParametricCRS` | A 1-dimensional coordinate reference system which uses parameter values or functions.
    `class` | `DefaultProjectedCRS` | A 2-dimensional coordinate reference system used to approximate the shape of the earth on a planar surface.
    `class` | `DefaultTemporalCRS` | A 1-dimensional coordinate reference system used for the recording of time.
    `class` | `DefaultVerticalCRS` | A 1-dimensional coordinate reference system used for recording heights or depths.

  - ### Uses of AbstractReferenceSystem in org.apache.sis.referencing.gazetteer

    Subclasses of AbstractReferenceSystem in org.apache.sis.referencing.gazetteer
    Modifier and Type | Class | Description
    --- | --- | ---
    `class` | `GeohashReferenceSystem` | Geographic coordinates represented as geohashes strings.
    `class` | `MilitaryGridReferenceSystem` | The Military Grid Reference System (MGRS).
    `class` | `ReferencingByIdentifiers` | Base class of reference systems that describe locations using geographic identifiers instead than coordinates.