EPSG:26731

NAD27 / Alaska zone 1

Available transformations
to EPSG:4326

Selected transformation

Method: NADCON

Grid Files: alaska.las alaska.los

Remarks: Parameter files are from NAD27 to NAD83 (2) (code 1243) 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: US survey foot

Geodetic CRS: NAD27

Datum: North American Datum 1927

Ellipsoid: Clarke 1866

Prime meridian: Greenwich

Data source: EPSG

Revision date: 1995-06-02

Center coordinates
-2016005.72 4462262.82

Projected bounds:
-10409459.11 -1444438.99
3597215.37 10821726.63

WGS84 bounds:
167.65 47.88
-129.99 74.71

United States (USA) - Alaska including EEZ.
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Definition: OGC Well Known Text 2 (2019)

BOUNDCRS[
    SOURCECRS[
        PROJCRS["NAD27 / Alaska zone 1",
            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["Alaska CS27 zone 1",
                METHOD["Hotine Oblique Mercator (variant A)",
                    ID["EPSG",9812]],
                PARAMETER["Latitude of projection centre",57,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8811]],
                PARAMETER["Longitude of projection centre",-133.666666666667,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8812]],
                PARAMETER["Azimuth of initial line",323.130102361111,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8813]],
                PARAMETER["Angle from Rectified to Skew Grid",323.130102361111,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8814]],
                PARAMETER["Scale factor on initial line",0.9999,
                    SCALEUNIT["unity",1],
                    ID["EPSG",8815]],
                PARAMETER["False easting",16404166.67,
                    LENGTHUNIT["US survey foot",0.304800609601219],
                    ID["EPSG",8806]],
                PARAMETER["False northing",-16404166.67,
                    LENGTHUNIT["US survey foot",0.304800609601219],
                    ID["EPSG",8807]]],
            CS[Cartesian,2],
                AXIS["easting (X)",east,
                    ORDER[1],
                    LENGTHUNIT["US survey foot",0.304800609601219]],
                AXIS["northing (Y)",north,
                    ORDER[2],
                    LENGTHUNIT["US survey foot",0.304800609601219]],
            USAGE[
                SCOPE["Engineering survey, topographic mapping."],
                AREA["United States (USA) - Alaska - east of 141°W; i.e. Panhandle."],
                BBOX[54.61,-141,60.35,-129.99]],
            ID["EPSG",26731]]],
    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 (85)",
        METHOD["NADCON",
            ID["EPSG",9613]],
        PARAMETERFILE["Latitude difference file","alaska.las"],
        PARAMETERFILE["Longitude difference file","alaska.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) - Alaska including EEZ."],
            BBOX[47.88,167.65,74.71,-129.99]],
        ID["EPSG",15864],
        REMARK["Parameter files are from NAD27 to NAD83 (2) (code 1243) 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 / Alaska zone 1",
        "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": "Alaska CS27 zone 1",
            "method": {
                "name": "Hotine Oblique Mercator (variant A)",
                "id": {
                    "authority": "EPSG",
                    "code": 9812
                }
            },
            "parameters": [
                {
                    "name": "Latitude of projection centre",
                    "value": 57,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8811
                    }
                },
                {
                    "name": "Longitude of projection centre",
                    "value": -133.666666666667,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8812
                    }
                },
                {
                    "name": "Azimuth of initial line",
                    "value": 323.130102361111,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8813
                    }
                },
                {
                    "name": "Angle from Rectified to Skew Grid",
                    "value": 323.130102361111,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8814
                    }
                },
                {
                    "name": "Scale factor on initial line",
                    "value": 0.9999,
                    "unit": "unity",
                    "id": {
                        "authority": "EPSG",
                        "code": 8815
                    }
                },
                {
                    "name": "False easting",
                    "value": 16404166.67,
                    "unit": {
                        "type": "LinearUnit",
                        "name": "US survey foot",
                        "conversion_factor": 0.304800609601219
                    },
                    "id": {
                        "authority": "EPSG",
                        "code": 8806
                    }
                },
                {
                    "name": "False northing",
                    "value": -16404166.67,
                    "unit": {
                        "type": "LinearUnit",
                        "name": "US survey foot",
                        "conversion_factor": 0.304800609601219
                    },
                    "id": {
                        "authority": "EPSG",
                        "code": 8807
                    }
                }
            ]
        },
        "coordinate_system": {
            "subtype": "Cartesian",
            "axis": [
                {
                    "name": "Easting",
                    "abbreviation": "X",
                    "direction": "east",
                    "unit": {
                        "type": "LinearUnit",
                        "name": "US survey foot",
                        "conversion_factor": 0.304800609601219
                    }
                },
                {
                    "name": "Northing",
                    "abbreviation": "Y",
                    "direction": "north",
                    "unit": {
                        "type": "LinearUnit",
                        "name": "US survey foot",
                        "conversion_factor": 0.304800609601219
                    }
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 26731
        }
    },
    "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 (85)",
        "method": {
            "name": "NADCON",
            "id": {
                "authority": "EPSG",
                "code": 9613
            }
        },
        "parameters": [
            {
                "name": "Latitude difference file",
                "value": "alaska.las",
                "id": {
                    "authority": "EPSG",
                    "code": 8657
                }
            },
            {
                "name": "Longitude difference file",
                "value": "alaska.los",
                "id": {
                    "authority": "EPSG",
                    "code": 8658
                }
            }
        ],
        "id": {
            "authority": "EPSG",
            "code": 15864
        }
    }
}