EPSG:11818

ETRS89-GRC [HTRS07] to ITRF2005 (1)

Attributes

Geodetic CRS: ETRS89-GRC [HTRS07]

Datum: Hellenic Terrestrial Reference System of 2007

Ellipsoid: GRS 1980

Prime meridian: Greenwich

Data source: EPSG

Information source: K. Katsampalos, C. Kotsakis and M. Gianniou, "Hellenic Terrestrial Reference System 2007 (HTRS07)", Bollettino di Geodesia e Scienze Affini, IGM Italy, vol LXIX-N. 2-3, May-December 2010.

Revision date: 2026-07-21

Scope: Merging of spatial data referenced to different national realizations of ETRS89 at the sub-decimetre level of accuracy.

Remarks: Determined in 2007 at EPN station AUT1 in Thessoloniki for ITRF2005 at epoch 2007.79 and applied at 98 stations of the HEPOS network. Adopted as relationship defining HTRS07 at epoch 2007.5. Accuracy is exact by definition at the ETRS89-GRC [HTRS07] anchor epoch of 2007.5, but deteriorates with time due to tectonic deformation and/or volcanic eruption. In southern Greece, velocities relative to ETRS89 exceed 3 cm/year, with co-seismic displacements of several cm and up to 40cm.

Method: Geocentric translations (geocentric domain)

Area of use: Greece - onshore and offshore. Includes Aegean Islands, Ionian Islands, Dodecanese Islands, Crete, and Mount Athos.

Description: (0,)

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SimpleMap
Greece - onshore and offshore. Includes Aegean Islands, Ionian Islands, Dodecanese Islands, Crete, and Mount Athos.

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Definition: OGC Well Known Text 2 (2019)

COORDINATEOPERATION["ETRS89-GRC [HTRS07] to ITRF2005 (1)",
    VERSION["IOGP-Grc 2007"],
    SOURCECRS[
        GEODCRS["ETRS89-GRC [HTRS07]",
            DATUM["Hellenic Terrestrial Reference System of 2007",
                ELLIPSOID["GRS 1980",6378137,298.257222101,
                    LENGTHUNIT["metre",1]],
                ANCHOREPOCH[2007.5]],
            PRIMEM["Greenwich",0,
                ANGLEUNIT["degree",0.0174532925199433]],
            CS[Cartesian,3],
                AXIS["(X)",geocentricX,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["(Y)",geocentricY,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
                AXIS["(Z)",geocentricZ,
                    ORDER[3],
                    LENGTHUNIT["metre",1]],
            ID["EPSG",11091]]],
    TARGETCRS[
        GEODCRS["ITRF2005",
            DYNAMIC[
                FRAMEEPOCH[2000]],
            DATUM["International Terrestrial Reference Frame 2005",
                ELLIPSOID["GRS 1980",6378137,298.257222101,
                    LENGTHUNIT["metre",1]]],
            PRIMEM["Greenwich",0,
                ANGLEUNIT["degree",0.0174532925199433]],
            CS[Cartesian,3],
                AXIS["(X)",geocentricX,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["(Y)",geocentricY,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
                AXIS["(Z)",geocentricZ,
                    ORDER[3],
                    LENGTHUNIT["metre",1]],
            ID["EPSG",4896]]],
    METHOD["Geocentric translations (geocentric domain)",
        ID["EPSG",1031]],
    PARAMETER["X-axis translation",-0.384,
        LENGTHUNIT["metre",1],
        ID["EPSG",8605]],
    PARAMETER["Y-axis translation",0.291,
        LENGTHUNIT["metre",1],
        ID["EPSG",8606]],
    PARAMETER["Z-axis translation",0.236,
        LENGTHUNIT["metre",1],
        ID["EPSG",8607]],
    OPERATIONACCURACY[0.8],
    USAGE[
        SCOPE["Merging of spatial data referenced to different national realizations of ETRS89 at the sub-decimetre level of accuracy."],
        AREA["Greece - onshore and offshore. Includes Aegean Islands, Ionian Islands, Dodecanese Islands, Crete, and Mount Athos."],
        BBOX[33.26,18.26,41.75,30.11]],
    ID["EPSG",11818],
    REMARK["Determined in 2007 at EPN station AUT1 in Thessoloniki for ITRF2005 at epoch 2007.79 and applied at 98 stations of the HEPOS network. Adopted as relationship defining HTRS07 at epoch 2007.5. Accuracy is exact by definition at the ETRS89-GRC [HTRS07] anchor epoch of 2007.5, but deteriorates with time due to tectonic deformation and/or volcanic eruption. In southern Greece, velocities relative to ETRS89 exceed 3 cm/year, with co-seismic displacements of several cm and up to 40cm."]]

Definition: PROJ.4

+proj=helmert +x=-0.384 +y=0.291 +z=0.236

Definition: JavaScript (Proj4js) 

proj4.defs("EPSG:11818","+proj=helmert +x=-0.384 +y=0.291 +z=0.236");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "Transformation",
    "name": "ETRS89-GRC [HTRS07] to ITRF2005 (1)",
    "source_crs": {
        "type": "GeodeticCRS",
        "name": "ETRS89-GRC [HTRS07]",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "Hellenic Terrestrial Reference System of 2007",
            "anchor_epoch": 2007.5,
            "ellipsoid": {
                "name": "GRS 1980",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257222101
            }
        },
        "coordinate_system": {
            "subtype": "Cartesian",
            "axis": [
                {
                    "name": "Geocentric X",
                    "abbreviation": "X",
                    "direction": "geocentricX",
                    "unit": "metre"
                },
                {
                    "name": "Geocentric Y",
                    "abbreviation": "Y",
                    "direction": "geocentricY",
                    "unit": "metre"
                },
                {
                    "name": "Geocentric Z",
                    "abbreviation": "Z",
                    "direction": "geocentricZ",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 11091
        },
        "remarks": "National realization of ETRS89 in Greece."
    },
    "target_crs": {
        "type": "GeodeticCRS",
        "name": "ITRF2005",
        "datum": {
            "type": "DynamicGeodeticReferenceFrame",
            "name": "International Terrestrial Reference Frame 2005",
            "frame_reference_epoch": 2000,
            "ellipsoid": {
                "name": "GRS 1980",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257222101
            }
        },
        "coordinate_system": {
            "subtype": "Cartesian",
            "axis": [
                {
                    "name": "Geocentric X",
                    "abbreviation": "X",
                    "direction": "geocentricX",
                    "unit": "metre"
                },
                {
                    "name": "Geocentric Y",
                    "abbreviation": "Y",
                    "direction": "geocentricY",
                    "unit": "metre"
                },
                {
                    "name": "Geocentric Z",
                    "abbreviation": "Z",
                    "direction": "geocentricZ",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 4896
        },
        "remarks": "Replaces ITRF2000 (CRS code 4919). Replaced by ITRF2008 (CRS code 5332)."
    },
    "method": {
        "name": "Geocentric translations (geocentric domain)",
        "id": {
            "authority": "EPSG",
            "code": 1031
        }
    },
    "parameters": [
        {
            "name": "X-axis translation",
            "value": -0.384,
            "unit": "metre",
            "id": {
                "authority": "EPSG",
                "code": 8605
            }
        },
        {
            "name": "Y-axis translation",
            "value": 0.291,
            "unit": "metre",
            "id": {
                "authority": "EPSG",
                "code": 8606
            }
        },
        {
            "name": "Z-axis translation",
            "value": 0.236,
            "unit": "metre",
            "id": {
                "authority": "EPSG",
                "code": 8607
            }
        }
    ],
    "accuracy": "0.8",
    "scope": "Merging of spatial data referenced to different national realizations of ETRS89 at the sub-decimetre level of accuracy.",
    "area": "Greece - onshore and offshore. Includes Aegean Islands, Ionian Islands, Dodecanese Islands, Crete, and Mount Athos.",
    "bbox": {
        "south_latitude": 33.26,
        "west_longitude": 18.26,
        "north_latitude": 41.75,
        "east_longitude": 30.11
    },
    "id": {
        "authority": "EPSG",
        "code": 11818
    },
    "remarks": "Determined in 2007 at EPN station AUT1 in Thessoloniki for ITRF2005 at epoch 2007.79 and applied at 98 stations of the HEPOS network. Adopted as relationship defining HTRS07 at epoch 2007.5. Accuracy is exact by definition at the ETRS89-GRC [HTRS07] anchor epoch of 2007.5, but deteriorates with time due to tectonic deformation and/or volcanic eruption. In southern Greece, velocities relative to ETRS89 exceed 3 cm/year, with co-seismic displacements of several cm and up to 40cm."
}

Definition: MapServer - MAPfile

PROJECTION
	"proj=helmert"
	"x=-0.384"
	"y=0.291"
	"z=0.236"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=helmert +x=-0.384 +y=0.291 +z=0.236">
	<Layer srs="+proj=helmert +x=-0.384 +y=0.291 +z=0.236">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 11818, 'EPSG', 11818, '+proj=helmert +x=-0.384 +y=0.291 +z=0.236', 'None');