REGCAN95 (EPSG:4081)
Sep 24,2026

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Introduction

REGCAN95 (EPSG:4081) is the official geodetic datum for the Canary Islands, Spain. Its official name is Red Geodesica de Canarias 1995. It uses the GRS 1980 reference ellipsoid and the Greenwich meridian as its prime meridian. It is a 2D geographic coordinate system, with coordinate units in degrees and coordinate axis order of geodetic latitude (northward) followed by geodetic longitude (eastward). Its coverage extends over the land territory and surrounding maritime areas of the Canary Islands, and it replaces the older Pico de las Nieves 1984 (PN84) datum. It is currently widely used in surveying and geographic information-related work as the horizontal component of the region's 3D coordinate system.

Coordinate System Composition

Datum definition: The geodetic datum is Red Geodesica de Canarias 1995, a regional geodetic datum dedicated to the Canary Islands, replacing the older PN84 datum.
Reference ellipsoid: Uses the GRS 1980 ellipsoid, with a semi-major axis of 6,378,137 meters and a flattening of 1/298.257222101.
Prime meridian: Uses Greenwich as the prime meridian, consistent with the internationally used 0° longitude reference.
Coordinate system type: Classified as a 2D ellipsoidal geographic coordinate system, with coordinate axes ordered as northward geodetic latitude followed by eastward geodetic longitude.
Units and coverage: Coordinate units are in degrees, and the coverage area encompasses the entire land territory and surrounding maritime areas of the Canary Islands, Spain.
Basic attributes: As the horizontal component of a 3D coordinate system, it is the core spatial reference for regional surveying in the Canary Islands and is also natively supported by major GIS platforms.

Pros

High regional fitting accuracy: As a regional geodetic datum dedicated to the Canary Islands, its reference ellipsoid (GRS 1980) and geodetic origin are optimized for the topography and geomorphology of the archipelago. Positioning accuracy within the islands is superior to directly using a generic global geodetic datum.
High compatibility with major ellipsoids: The GRS 1980 ellipsoid it adopts is also used by modern geodetic datums such as ITRF and ETRS89, so transformation parameters with major international coordinate systems are mature, enabling reliable global data integration.
Official authoritative backing: It is the legal datum used in data published by the official surveying agencies of the Canary Islands, Spain. Existing regional surveying results, cadastral data, and urban planning data are all based on this datum, so using this coordinate system allows direct use of local official data without additional conversion.
Comprehensive software platform support: It is a standard coordinate system registered with EPSG (code 4081) and is natively recognized and supported by major GIS software such as ArcGIS, QGIS, and Proj, offering ease of use.
Rich transformation resources: Spanish official agencies provide corresponding NTv2 grid transformation files (such as transformations between REGCAN95 and ED50, ETRS89), enabling high-precision coordinate transformation.

Cons

Very limited coverage: It only covers the Canary Islands and a narrow surrounding maritime area. Using it outside this region significantly degrades coordinate accuracy and applicability, making it unsuitable for broader spatial analysis.
No independent height datum: This coordinate system itself is only a 2D horizontal datum and does not directly include an official vertical height reference. 3D positioning requires separately referencing local height datums such as the Canary Islands tide gauge height system.
Errors in direct conversion with WGS84: The default 7-parameter transformation values between this datum and WGS84 are all set to zero in EPSG. Therefore, directly treating the two as the same datum may produce position errors on the order of several meters. Ensuring high precision requires dedicated transformation parameters or grid files.
Differences from mainland Spain's datums: Mainland Spain primarily uses the ED50 and ETRS89 datums, requiring additional coordinate transformation with REGCAN95. As a result, data processing becomes more complex in wide-area projects.
Timeliness constraints: As a datum established in 1995, its consistency with the current ITRF framework gradually drifts over time due to crustal deformation and the development of modern GNSS technology. Maintaining accuracy requires periodic updates to transformation parameters.

Application Scenario

REGCAN95 (EPSG:4081) is primarily used for official surveying and cadastral management in the Canary Islands. It is the legal spatial reference for local land registration, urban planning, and infrastructure construction, and is also widely used in specialized fields such as geological hazard monitoring, environmental assessment, and marine resource management within the archipelago. In academic research and engineering surveying, it functions as the foundational coordinate framework supporting high-precision positioning in the region. In combination with NTv2 grid files, it also enables mutual transformation with global geodetic datums, meeting the needs of wide-area data integration.