EPSG:26721

NAD27 / UTM zone 21N

Available transformations
to EPSG:4326

Selected transformation

Method: NADCON

Grid Files: conus.las conus.los

Remarks: Parameter files are from NAD27 to NAD83 (1) (code 1241) assuming that NAD83 is equivalent to WGS 84 within the accuracy of this tfm. Uses NADCON method which expects longitudes positive west; EPSG CRS codes 4267 and 4326 have longitudes positive east.

Information source: OGP

Revision date: 2021-09-10

Attributes

Unit: metre

Geodetic CRS: NAD27

Datum: North American Datum 1927

Ellipsoid: Clarke 1866

Prime meridian: Greenwich

Data source: EPSG

Revision date: 2011-07-20

Scope: Engineering survey, topographic mapping.

Remarks: In Quebec replaced by NAD27(CGQ77) / UTM zone 21N (code 2035).

Area of use: Canada between 60°W and 54°W, onshore and offshore - Newfoundland and Labrador; Quebec.

Coordinate system: Cartesian 2D CS. Axes: easting, northing (E,N). Orientations: east, north. UoM: m.

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Definition: OGC Well Known Text 2 (2019)

BOUNDCRS[
    SOURCECRS[
        PROJCRS["NAD27 / UTM zone 21N",
            BASEGEOGCRS["NAD27",
                DATUM["North American Datum 1927",
                    ELLIPSOID["Clarke 1866",6378206.4,294.978698213898,
                        LENGTHUNIT["metre",1]]],
                PRIMEM["Greenwich",0,
                    ANGLEUNIT["degree",0.0174532925199433]],
                ID["EPSG",4267]],
            CONVERSION["UTM zone 21N",
                METHOD["Transverse Mercator",
                    ID["EPSG",9807]],
                PARAMETER["Latitude of natural origin",0,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8801]],
                PARAMETER["Longitude of natural origin",-57,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8802]],
                PARAMETER["Scale factor at natural origin",0.9996,
                    SCALEUNIT["unity",1],
                    ID["EPSG",8805]],
                PARAMETER["False easting",500000,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8806]],
                PARAMETER["False northing",0,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8807]]],
            CS[Cartesian,2],
                AXIS["(E)",east,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["(N)",north,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
            USAGE[
                SCOPE["Engineering survey, topographic mapping."],
                AREA["Canada between 60°W and 54°W, onshore and offshore - Newfoundland and Labrador; Quebec."],
                BBOX[40.57,-60,68.93,-54]],
            ID["EPSG",26721]]],
    TARGETCRS[
        GEOGCRS["WGS 84",
            ENSEMBLE["World Geodetic System 1984 ensemble",
                MEMBER["World Geodetic System 1984 (Transit)"],
                MEMBER["World Geodetic System 1984 (G730)"],
                MEMBER["World Geodetic System 1984 (G873)"],
                MEMBER["World Geodetic System 1984 (G1150)"],
                MEMBER["World Geodetic System 1984 (G1674)"],
                MEMBER["World Geodetic System 1984 (G1762)"],
                MEMBER["World Geodetic System 1984 (G2139)"],
                ELLIPSOID["WGS 84",6378137,298.257223563,
                    LENGTHUNIT["metre",1]],
                ENSEMBLEACCURACY[2.0]],
            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]],
            USAGE[
                SCOPE["Horizontal component of 3D system."],
                AREA["World."],
                BBOX[-90,-180,90,180]],
            ID["EPSG",4326]]],
    ABRIDGEDTRANSFORMATION["NAD27 to WGS 84 (79)",
        METHOD["NADCON",
            ID["EPSG",9613]],
        PARAMETERFILE["Latitude difference file","conus.las"],
        PARAMETERFILE["Longitude difference file","conus.los"],
        USAGE[
            SCOPE["(null/copy) Approximation for medium and low accuracy applications assuming equality between plate-fixed static and earth-fixed dynamic CRSs, ignoring static/dynamic CRS differences."],
            AREA["United States (USA) - CONUS including EEZ - onshore and offshore - Alabama; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming. US Gulf of Mexico (GoM) OCS."],
            BBOX[23.81,-129.17,49.38,-65.69]],
        ID["EPSG",15851],
        REMARK["Parameter files are from NAD27 to NAD83 (1) (code 1241) assuming that NAD83 is equivalent to WGS 84 within the accuracy of this tfm. Uses NADCON method which expects longitudes positive west; EPSG CRS codes 4267 and 4326 have longitudes positive east."]]]

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "BoundCRS",
    "source_crs": {
        "type": "ProjectedCRS",
        "name": "NAD27 / UTM zone 21N",
        "base_crs": {
            "name": "NAD27",
            "datum": {
                "type": "GeodeticReferenceFrame",
                "name": "North American Datum 1927",
                "ellipsoid": {
                    "name": "Clarke 1866",
                    "semi_major_axis": 6378206.4,
                    "semi_minor_axis": 6356583.8
                }
            },
            "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": 4267
            }
        },
        "conversion": {
            "name": "UTM zone 21N",
            "method": {
                "name": "Transverse Mercator",
                "id": {
                    "authority": "EPSG",
                    "code": 9807
                }
            },
            "parameters": [
                {
                    "name": "Latitude of natural origin",
                    "value": 0,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8801
                    }
                },
                {
                    "name": "Longitude of natural origin",
                    "value": -57,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8802
                    }
                },
                {
                    "name": "Scale factor at natural origin",
                    "value": 0.9996,
                    "unit": "unity",
                    "id": {
                        "authority": "EPSG",
                        "code": 8805
                    }
                },
                {
                    "name": "False easting",
                    "value": 500000,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8806
                    }
                },
                {
                    "name": "False northing",
                    "value": 0,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8807
                    }
                }
            ]
        },
        "coordinate_system": {
            "subtype": "Cartesian",
            "axis": [
                {
                    "name": "Easting",
                    "abbreviation": "E",
                    "direction": "east",
                    "unit": "metre"
                },
                {
                    "name": "Northing",
                    "abbreviation": "N",
                    "direction": "north",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 26721
        }
    },
    "target_crs": {
        "type": "GeographicCRS",
        "name": "WGS 84",
        "datum_ensemble": {
            "name": "World Geodetic System 1984 ensemble",
            "members": [
                {
                    "name": "World Geodetic System 1984 (Transit)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1166
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G730)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1152
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G873)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1153
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G1150)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1154
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G1674)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1155
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G1762)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1156
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G2139)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1309
                    }
                }
            ],
            "ellipsoid": {
                "name": "WGS 84",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257223563
            },
            "accuracy": "2.0",
            "id": {
                "authority": "EPSG",
                "code": 6326
            }
        },
        "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": 4326
        }
    },
    "transformation": {
        "name": "NAD27 to WGS 84 (79)",
        "method": {
            "name": "NADCON",
            "id": {
                "authority": "EPSG",
                "code": 9613
            }
        },
        "parameters": [
            {
                "name": "Latitude difference file",
                "value": "conus.las",
                "id": {
                    "authority": "EPSG",
                    "code": 8657
                }
            },
            {
                "name": "Longitude difference file",
                "value": "conus.los",
                "id": {
                    "authority": "EPSG",
                    "code": 8658
                }
            }
        ],
        "id": {
            "authority": "EPSG",
            "code": 15851
        }
    }
}