NAD27 / US National Atlas Equal Area

Selected transformation

Method: NTv2

Grid Files: NTv2_0.gsb

Remarks: Uses NTv2 data files. Replaces NTv1 (transformation code 1312) except in Quebec. Input expects longitudes to be positive west; EPSG GeogCRS NAD27 (code 4267) and (code 4269) have longitudes positive east. May be used as tfm to WGS 84 - see code 1693.

Information source: NR Canada, https://www.nrcan.gc.ca/

Revision date: 2021-08-26

Attributes

Unit: metre

Geodetic CRS: NAD27

Datum: North American Datum 1927

Ellipsoid: Clarke 1866

Prime meridian: Greenwich

Data source: EPSG

Information source: United States Geological Survey, Western Geographic Science Center

Revision date: 2020-03-26

Scope: Statistical analysis.

Remarks: Uses spherical projection formulas. USGS documentation describes sphere as derived from GRS80/WGS 84 ellipsoid but that actually used is Clarke 1866. For 1:1million and smaller scale maps there is no significant difference.

Area of use: United States (USA) - onshore and offshore.

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

Covered area powered by MapTiler

Center coordinates
399925.56 1857578.2

Projected bounds:
-2891738.55 1091149.74
-529125.74 4330307.81

WGS84 bounds:
-141.01 40.0
-44.0 83.17

Canada - onshore - Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Northwest Territories; Nova Scotia; Nunavut; Ontario; Prince Edward Island; Quebec; Saskatchewan; Yukon; offshore east coast west of 44°W and north of 40°N.

Definition: OGC Well Known Text 2 (2019)

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BOUNDCRS[
    SOURCECRS[
        PROJCRS["NAD27 / US National Atlas Equal Area",
            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["US National Atlas Equal Area",
                METHOD["Lambert Azimuthal Equal Area (Spherical)",
                    ID["EPSG",1027]],
                PARAMETER["Latitude of natural origin",45,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8801]],
                PARAMETER["Longitude of natural origin",-100,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8802]],
                PARAMETER["False easting",0,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8806]],
                PARAMETER["False northing",0,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8807]]],
            CS[Cartesian,2],
                AXIS["easting (X)",east,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["northing (Y)",north,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
            USAGE[
                SCOPE["Statistical analysis."],
                AREA["United States (USA) - onshore and offshore."],
                BBOX[15.56,167.65,74.71,-65.69]],
            ID["EPSG",9311]]],
    TARGETCRS[
        GEOGCRS["NAD83",
            DATUM["North American Datum 1983",
                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]],
            USAGE[
                SCOPE["Geodesy."],
                AREA["North America - onshore and offshore: Canada - Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Northwest Territories; Nova Scotia; Nunavut; Ontario; Prince Edward Island; Quebec; Saskatchewan; Yukon. Puerto Rico. United States (USA) - Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; 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 Virgin Islands. British Virgin Islands."],
                BBOX[14.92,167.65,86.45,-40.73]],
            ID["EPSG",4269]]],
    ABRIDGEDTRANSFORMATION["NAD27 to NAD83 (4)",
        METHOD["NTv2",
            ID["EPSG",9615]],
        PARAMETERFILE["Latitude and longitude difference file","NTv2_0.gsb"],
        USAGE[
            SCOPE["Transformation of coordinates at 1m to 2m level of accuracy."],
            AREA["Canada - onshore - Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Northwest Territories; Nova Scotia; Nunavut; Ontario; Prince Edward Island; Quebec; Saskatchewan; Yukon; offshore east coast west of 44°W and north of 40°N."],
            BBOX[40,-141.01,83.17,-44]],
        ID["EPSG",1313],
        REMARK["Uses NTv2 data files. Replaces NTv1 (transformation code 1312) except in Quebec. Input expects longitudes to be positive west; EPSG GeogCRS NAD27 (code 4267) and (code 4269) have longitudes positive east. May be used as tfm to WGS 84 - see code 1693."]]]

Definition: PROJ.4

+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +datum=NAD27 +units=m +no_defs +type=crs

Definition: JavaScript (Proj4js)

proj4.defs("EPSG:9311","+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +datum=NAD27 +units=m +no_defs +type=crs");

Definition: JSON

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{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "BoundCRS",
    "source_crs": {
        "type": "ProjectedCRS",
        "name": "NAD27 / US National Atlas Equal Area",
        "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": "US National Atlas Equal Area",
            "method": {
                "name": "Lambert Azimuthal Equal Area (Spherical)",
                "id": {
                    "authority": "EPSG",
                    "code": 1027
                }
            },
            "parameters": [
                {
                    "name": "Latitude of natural origin",
                    "value": 45,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8801
                    }
                },
                {
                    "name": "Longitude of natural origin",
                    "value": -100,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8802
                    }
                },
                {
                    "name": "False easting",
                    "value": 0,
                    "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": "X",
                    "direction": "east",
                    "unit": "metre"
                },
                {
                    "name": "Northing",
                    "abbreviation": "Y",
                    "direction": "north",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 9311
        }
    },
    "target_crs": {
        "type": "GeographicCRS",
        "name": "NAD83",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "North American Datum 1983",
            "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": 4269
        }
    },
    "transformation": {
        "name": "NAD27 to NAD83 (4)",
        "method": {
            "name": "NTv2",
            "id": {
                "authority": "EPSG",
                "code": 9615
            }
        },
        "parameters": [
            {
                "name": "Latitude and longitude difference file",
                "value": "NTv2_0.gsb",
                "id": {
                    "authority": "EPSG",
                    "code": 8656
                }
            }
        ],
        "id": {
            "authority": "EPSG",
            "code": 1313
        }
    }
}

Definition: MapServer - MAPfile

PROJECTION
	"proj=laea"
	"R_A"
	"lat_0=45"
	"lon_0=-100"
	"x_0=0"
	"y_0=0"
	"datum=NAD27"
	"units=m"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +datum=NAD27 +units=m +no_defs +type=crs">
	<Layer srs="+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +datum=NAD27 +units=m +no_defs +type=crs">
	</Layer>
</Map>

EPSG:9311