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Name: NAD27 to WGS 84 (33)
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
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.
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","ca_nrc_ntv2_0.tif"]], 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)
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["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)"], MEMBER["World Geodetic System 1984 (G2296)"], 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 (33)", METHOD["NTv2", ID["EPSG",9615]], PARAMETERFILE["Latitude and longitude difference file","NTv2_0.gsb"], 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["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",1693], REMARK["Parameter file is from NAD27 to NAD83 (4) (code 1313) assuming that NAD83 is equivalent to WGS 84 within the accuracy of the transformation."]]]
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","ca_nrc_ntv2_0.tif"]], PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]], PROJECTION["Lambert_Azimuthal_Equal_Area"], PARAMETER["Latitude of natural origin",45.0], PARAMETER["Longitude of natural origin",-100.0], PARAMETER["False easting",0.0], PARAMETER["False northing",0.0], UNIT["Meter",1.0]]
Definition: JSON
{ "$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": { "type": "GeographicCRS", "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 }, "remarks": "Note: this CRS includes longitudes which are POSITIVE EAST. Replaced by NAD27(76) (code 4608) in Ontario, CGQ77 (code 4609) in Quebec, Mexican Datum of 1993 (code 4483) in Mexico, NAD83 (code 4269) in Canada (excl. Ontario & Quebec) & USA." }, "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": "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 } }, { "name": "World Geodetic System 1984 (G2296)", "id": { "authority": "EPSG", "code": 1383 } } ], "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 (33)", "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": 1693 } } }
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","ca_nrc_ntv2_0.tif"]],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: 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=ca_nrc_ntv2_0.tif +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=ca_nrc_ntv2_0.tif +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=ca_nrc_ntv2_0.tif +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","ca_nrc_ntv2_0.tif"]],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"]]');
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