EPSG:12204

ETRS89-GRC [HTRS07] to GGRS87 (2)

Attributes

Geodetic CRS: ETRS89-GRC [HTRS07]

Datum: Hellenic Terrestrial Reference System of 2007

Ellipsoid: GRS 1980

Prime meridian: Greenwich

Data source: EPSG

Information source: Ktimatologio S.A. (Hellenic Cadastre) Geodetic Department, "Coordinate Transformation Model between the HEPOS Reference System (HTRS07) and the Hellenic Geodetic Reference System (GGRS87)", October 2008. https://www.hepos.gr/

Revision date: 2026-07-21

Scope: Transformation of coordinates at 1m to 2m level of accuracy.

Remarks: Derived at 2199 locations throughout Greece. Accuracy evaluated at 231 locations: maximum residual 2.59m, RMS 0.68m. For higher accuracy transformation including distortion correction grid see ETRS89-GRC [HTRS07] to GGRS87 (3) (code 12207).

Method: Coordinate Frame rotation (geog2D domain)

Area of use: Greece - onshore west of 28°51'E.

Description: (0,)

Covered area powered by MapTiler MapTiler logo
SimpleMap
Greece - onshore west of 28°51'E.

MapTiler banner

Definition: OGC Well Known Text 2 (2019)

COORDINATEOPERATION["ETRS89-GRC [HTRS07] to GGRS87 (2)",
    VERSION["Kt-Grc 2007 Helmert"],
    SOURCECRS[
        GEOGCRS["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[ellipsoidal,2],
                AXIS["geodetic latitude (Lat)",north,
                    ORDER[1],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["geodetic longitude (Lon)",east,
                    ORDER[2],
                    ANGLEUNIT["degree",0.0174532925199433]],
            ID["EPSG",11093]]],
    TARGETCRS[
        GEOGCRS["GGRS87",
            DATUM["Greek Geodetic Reference System 1987",
                ELLIPSOID["GRS 1980",6378137,298.257222101,
                    LENGTHUNIT["metre",1]]],
            PRIMEM["Greenwich",0,
                ANGLEUNIT["degree",0.0174532925199433]],
            CS[ellipsoidal,2],
                AXIS["geodetic latitude (Lat)",north,
                    ORDER[1],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["geodetic longitude (Lon)",east,
                    ORDER[2],
                    ANGLEUNIT["degree",0.0174532925199433]],
            ID["EPSG",4121]]],
    METHOD["Coordinate Frame rotation (geog2D domain)",
        ID["EPSG",9607]],
    PARAMETER["X-axis translation",203.437,
        LENGTHUNIT["metre",1],
        ID["EPSG",8605]],
    PARAMETER["Y-axis translation",-73.461,
        LENGTHUNIT["metre",1],
        ID["EPSG",8606]],
    PARAMETER["Z-axis translation",-243.594,
        LENGTHUNIT["metre",1],
        ID["EPSG",8607]],
    PARAMETER["X-axis rotation",-0.17,
        ANGLEUNIT["arc-second",4.84813681109536E-06],
        ID["EPSG",8608]],
    PARAMETER["Y-axis rotation",-0.06,
        ANGLEUNIT["arc-second",4.84813681109536E-06],
        ID["EPSG",8609]],
    PARAMETER["Z-axis rotation",-0.151,
        ANGLEUNIT["arc-second",4.84813681109536E-06],
        ID["EPSG",8610]],
    PARAMETER["Scale difference",-0.294,
        SCALEUNIT["parts per million",1E-06],
        ID["EPSG",8611]],
    OPERATIONACCURACY[1.0],
    USAGE[
        SCOPE["Transformation of coordinates at 1m to 2m level of accuracy."],
        AREA["Greece - onshore west of 28°51'E."],
        BBOX[34.75,19.57,41.75,28.3]],
    ID["EPSG",12204],
    REMARK["Derived at 2199 locations throughout Greece. Accuracy evaluated at 231 locations: maximum residual 2.59m, RMS 0.68m. For higher accuracy transformation including distortion correction grid see ETRS89-GRC [HTRS07] to GGRS87 (3) (code 12207)."]]

Definition: PROJ.4

+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=GRS80 +step +proj=helmert +x=203.437 +y=-73.461 +z=-243.594 +rx=-0.17 +ry=-0.06 +rz=-0.151 +s=-0.294 +convention=coordinate_frame +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1

Definition: JavaScript (Proj4js) 

proj4.defs("EPSG:12204","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=GRS80 +step +proj=helmert +x=203.437 +y=-73.461 +z=-243.594 +rx=-0.17 +ry=-0.06 +rz=-0.151 +s=-0.294 +convention=coordinate_frame +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "Transformation",
    "name": "ETRS89-GRC [HTRS07] to GGRS87 (2)",
    "source_crs": {
        "type": "GeographicCRS",
        "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": "ellipsoidal",
            "axis": [
                {
                    "name": "Geodetic latitude",
                    "abbreviation": "Lat",
                    "direction": "north",
                    "unit": "degree"
                },
                {
                    "name": "Geodetic longitude",
                    "abbreviation": "Lon",
                    "direction": "east",
                    "unit": "degree"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 11093
        },
        "remarks": "Horizontal component of national realization of ETRS89 in Greece."
    },
    "target_crs": {
        "type": "GeographicCRS",
        "name": "GGRS87",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "Greek Geodetic Reference System 1987",
            "ellipsoid": {
                "name": "GRS 1980",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257222101
            }
        },
        "coordinate_system": {
            "subtype": "ellipsoidal",
            "axis": [
                {
                    "name": "Geodetic latitude",
                    "abbreviation": "Lat",
                    "direction": "north",
                    "unit": "degree"
                },
                {
                    "name": "Geodetic longitude",
                    "abbreviation": "Lon",
                    "direction": "east",
                    "unit": "degree"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 4121
        }
    },
    "method": {
        "name": "Coordinate Frame rotation (geog2D domain)",
        "id": {
            "authority": "EPSG",
            "code": 9607
        }
    },
    "parameters": [
        {
            "name": "X-axis translation",
            "value": 203.437,
            "unit": "metre",
            "id": {
                "authority": "EPSG",
                "code": 8605
            }
        },
        {
            "name": "Y-axis translation",
            "value": -73.461,
            "unit": "metre",
            "id": {
                "authority": "EPSG",
                "code": 8606
            }
        },
        {
            "name": "Z-axis translation",
            "value": -243.594,
            "unit": "metre",
            "id": {
                "authority": "EPSG",
                "code": 8607
            }
        },
        {
            "name": "X-axis rotation",
            "value": -0.17,
            "unit": {
                "type": "AngularUnit",
                "name": "arc-second",
                "conversion_factor": 4.84813681109536e-06
            },
            "id": {
                "authority": "EPSG",
                "code": 8608
            }
        },
        {
            "name": "Y-axis rotation",
            "value": -0.06,
            "unit": {
                "type": "AngularUnit",
                "name": "arc-second",
                "conversion_factor": 4.84813681109536e-06
            },
            "id": {
                "authority": "EPSG",
                "code": 8609
            }
        },
        {
            "name": "Z-axis rotation",
            "value": -0.151,
            "unit": {
                "type": "AngularUnit",
                "name": "arc-second",
                "conversion_factor": 4.84813681109536e-06
            },
            "id": {
                "authority": "EPSG",
                "code": 8610
            }
        },
        {
            "name": "Scale difference",
            "value": -0.294,
            "unit": {
                "type": "ScaleUnit",
                "name": "parts per million",
                "conversion_factor": 1e-06
            },
            "id": {
                "authority": "EPSG",
                "code": 8611
            }
        }
    ],
    "accuracy": "1.0",
    "scope": "Transformation of coordinates at 1m to 2m level of accuracy.",
    "area": "Greece - onshore west of 28°51'E.",
    "bbox": {
        "south_latitude": 34.75,
        "west_longitude": 19.57,
        "north_latitude": 41.75,
        "east_longitude": 28.3
    },
    "id": {
        "authority": "EPSG",
        "code": 12204
    },
    "remarks": "Derived at 2199 locations throughout Greece. Accuracy evaluated at 231 locations: maximum residual 2.59m, RMS 0.68m. For higher accuracy transformation including distortion correction grid see ETRS89-GRC [HTRS07] to GGRS87 (3) (code 12207)."
}

Definition: MapServer - MAPfile

PROJECTION
	"proj=pipeline"
	"step"
	"proj=axisswap"
	"order=2,1"
	"step"
	"proj=unitconvert"
	"xy_in=deg"
	"xy_out=rad"
	"step"
	"proj=push"
	"v_3"
	"step"
	"proj=cart"
	"ellps=GRS80"
	"step"
	"proj=helmert"
	"x=203.437"
	"y=-73.461"
	"z=-243.594"
	"rx=-0.17"
	"ry=-0.06"
	"rz=-0.151"
	"s=-0.294"
	"convention=coordinate_frame"
	"step"
	"inv"
	"proj=cart"
	"ellps=GRS80"
	"step"
	"proj=pop"
	"v_3"
	"step"
	"proj=unitconvert"
	"xy_in=rad"
	"xy_out=deg"
	"step"
	"proj=axisswap"
	"order=2,1"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=GRS80 +step +proj=helmert +x=203.437 +y=-73.461 +z=-243.594 +rx=-0.17 +ry=-0.06 +rz=-0.151 +s=-0.294 +convention=coordinate_frame +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	<Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=GRS80 +step +proj=helmert +x=203.437 +y=-73.461 +z=-243.594 +rx=-0.17 +ry=-0.06 +rz=-0.151 +s=-0.294 +convention=coordinate_frame +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 12204, 'EPSG', 12204, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=GRS80 +step +proj=helmert +x=203.437 +y=-73.461 +z=-243.594 +rx=-0.17 +ry=-0.06 +rz=-0.151 +s=-0.294 +convention=coordinate_frame +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');