EPSG:9311

NAD27 / US National Atlas Equal Area

Available transformations
to EPSG:4326

Selected transformation

Method: NTv2

Grid Files: NTv2_0.gsb

Remarks: Parameter file is from NAD27 to NAD83 (4) (code 1313) assuming that NAD83 is equivalent to WGS 84 within the accuracy of the transformation.

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

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.

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Definition: OGC Well Known Text

PROJCS["NAD27 / US National Atlas Equal Area",
    GEOGCS["NAD27",
        DATUM["North_American_Datum_1927",
            SPHEROID["Clarke 1866",6378206.4,294.978698213898],
            EXTENSION["PROJ4_GRIDS","NTv2_0.gsb"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4267"]],
    PROJECTION["Lambert_Azimuthal_Equal_Area"],
    PARAMETER["latitude_of_center",45],
    PARAMETER["longitude_of_center",-100],
    PARAMETER["false_easting",0],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","9311"]]

Definition: OGC Well Known Text 2 (2019)

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]]

Definition: ESRI Well Known Text

PROJCS["NAD27_US_National_Atlas_Equal_Area",
    GEOGCS["GCS_North_American_1927",
        DATUM["D_North_American_1927",
            SPHEROID["Clarke_1866",6378206.4,294.978698213898],
            EXTENSION["PROJ4_GRIDS","NTv2_0.gsb"]],
        PRIMEM["Greenwich",0.0],
        UNIT["Degree",0.0174532925199433]],
    PROJECTION["Lambert_Azimuthal_Equal_Area"],
    PARAMETER["latitude_of_center",45.0],
    PARAMETER["longitude_of_center",-100.0],
    PARAMETER["false_easting",0.0],
    PARAMETER["false_northing",0.0],
    UNIT["Meter",1.0]]

Definition: PROJ.4

+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +ellps=clrk66 +nadgrids=NTv2_0.gsb +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 +ellps=clrk66 +nadgrids=NTv2_0.gsb +units=m +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "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,
                "inverse_flattening": 294.978698213898
            }
        },
        "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"
            }
        ]
    },
    "scope": "Statistical analysis.",
    "area": "United States (USA) - onshore and offshore.",
    "bbox": {
        "south_latitude": 15.56,
        "west_longitude": 167.65,
        "north_latitude": 74.71,
        "east_longitude": -65.69
    },
    "id": {
        "authority": "EPSG",
        "code": 9311
    }
}

Definition: GeoServer

9311=PROJCS["NAD27 / US National Atlas Equal Area",GEOGCS["NAD27",DATUM["North_American_Datum_1927",SPHEROID["Clarke 1866",6378206.4,294.978698213898],EXTENSION["PROJ4_GRIDS","NTv2_0.gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4267"]],PROJECTION["Lambert_Azimuthal_Equal_Area"],PARAMETER["latitude_of_center",45],PARAMETER["longitude_of_center",-100],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","9311"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=laea"
	"R_A"
	"lat_0=45"
	"lon_0=-100"
	"x_0=0"
	"y_0=0"
	"ellps=clrk66"
	"nadgrids=NTv2_0.gsb"
	"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 +ellps=clrk66 +nadgrids=NTv2_0.gsb +units=m +no_defs +type=crs">
	<Layer srs="+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +ellps=clrk66 +nadgrids=NTv2_0.gsb +units=m +no_defs +type=crs">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 9311, 'EPSG', 9311, '+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +ellps=clrk66 +nadgrids=NTv2_0.gsb +units=m +no_defs +type=crs', 'PROJCS["NAD27 / US National Atlas Equal Area",GEOGCS["NAD27",DATUM["North_American_Datum_1927",SPHEROID["Clarke 1866",6378206.4,294.978698213898],EXTENSION["PROJ4_GRIDS","NTv2_0.gsb"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4267"]],PROJECTION["Lambert_Azimuthal_Equal_Area"],PARAMETER["latitude_of_center",45],PARAMETER["longitude_of_center",-100],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","9311"]]');