Name: NAD27 to NAD83(CSRS) (1)
Method: NTv2
Grid Files: QUE27-98.gsb
Remarks: Uses NT method which expects longitudes positive west; EPSG GeogCRSs NAD27 (code 4267) and NAD83(CSRS) (code 4617) have longitudes positive east. Can be taken as an approximate transformation NAD27 to WGS 84 - see code 1692.
Information source: Geodetic Service of Quebec. Contact alain.bernard@mrn.gouv.qc.ca
Revision date: 2002-07-13
Unit: US survey foot
Geodetic CRS: NAD27
Datum: North American Datum 1927
Ellipsoid: Clarke 1866
Prime meridian: Greenwich
Data source: EPSG
Information source: OGP
Revision date: 2025-07-10
Scope: No official usage.
Remarks: This system is NOT used for oil industry purposes. Use NAD27 / Louisiana South (CRS code 26782) in state waters and on LA OCS shelf and NAD27 / BLM (CRS codes 32065-66) in OCS deep water protraction areas.
Area of use: United States (USA) - central Gulf of Mexico outer continental shelf (GoM OCS) planning area, deep water portion.
Coordinate system: Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: ftUS.
Center coordinates
7570109.52 11160310.69
Projected bounds:
4459409.75 7290411.67
11224817.38 15499617.4
WGS84 bounds:
-79.85 44.99
-57.1 62.62
Definition: OGC Well Known Text 2 (2019)
BOUNDCRS[ SOURCECRS[ PROJCRS["NAD27 / Louisiana Offshore", 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["Louisiana CS27 Offshore zone", METHOD["Lambert Conic Conformal (2SP)", ID["EPSG",9802]], PARAMETER["Latitude of false origin",25.6666666666667, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8821]], PARAMETER["Longitude of false origin",-91.3333333333333, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8822]], PARAMETER["Latitude of 1st standard parallel",27.8333333333333, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8823]], PARAMETER["Latitude of 2nd standard parallel",26.1666666666667, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8824]], PARAMETER["Easting at false origin",2000000, LENGTHUNIT["US survey foot",0.304800609601219], ID["EPSG",8826]], PARAMETER["Northing at false origin",0, LENGTHUNIT["US survey foot",0.304800609601219], ID["EPSG",8827]]], 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["No official usage."], AREA["United States (USA) - central Gulf of Mexico outer continental shelf (GoM OCS) planning area, deep water portion."], BBOX[25.58,-93.38,29.35,-86.53]], ID["EPSG",32099]]], TARGETCRS[ GEOGCRS["NAD83(CSRS)", DATUM["NAD83 Canadian Spatial Reference System", 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["Horizontal component of 3D system."], AREA["Canada - onshore and offshore - Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Northwest Territories; Nova Scotia; Nunavut; Ontario; Prince Edward Island; Quebec; Saskatchewan; Yukon."], BBOX[38.21,-141.01,86.46,-40.73]], ID["EPSG",4617], REMARK["Includes all versions of NAD83(CSRS) from v2 [CSRS98] onwards without specific identification. As such it has an accuracy of approximately 1m. Note: this CRS includes longitudes which are POSITIVE EAST."]]], ABRIDGEDTRANSFORMATION["NAD27 to NAD83(CSRS) (1)", METHOD["NTv2", ID["EPSG",9615]], PARAMETERFILE["Latitude and longitude difference file","QUE27-98.gsb"], USAGE[ SCOPE["Transformation of coordinates at 1m to 2m level of accuracy."], AREA["Canada - Quebec."], BBOX[44.99,-79.85,62.62,-57.1]], ID["EPSG",1844], REMARK["Uses NT method which expects longitudes positive west; EPSG GeogCRSs NAD27 (code 4267) and NAD83(CSRS) (code 4617) have longitudes positive east. Can be taken as an approximate transformation NAD27 to WGS 84 - see code 1692."]]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "BoundCRS", "source_crs": { "type": "ProjectedCRS", "name": "NAD27 / Louisiana Offshore", "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": "Louisiana CS27 Offshore zone", "method": { "name": "Lambert Conic Conformal (2SP)", "id": { "authority": "EPSG", "code": 9802 } }, "parameters": [ { "name": "Latitude of false origin", "value": 25.6666666666667, "unit": "degree", "id": { "authority": "EPSG", "code": 8821 } }, { "name": "Longitude of false origin", "value": -91.3333333333333, "unit": "degree", "id": { "authority": "EPSG", "code": 8822 } }, { "name": "Latitude of 1st standard parallel", "value": 27.8333333333333, "unit": "degree", "id": { "authority": "EPSG", "code": 8823 } }, { "name": "Latitude of 2nd standard parallel", "value": 26.1666666666667, "unit": "degree", "id": { "authority": "EPSG", "code": 8824 } }, { "name": "Easting at false origin", "value": 2000000, "unit": { "type": "LinearUnit", "name": "US survey foot", "conversion_factor": 0.304800609601219 }, "id": { "authority": "EPSG", "code": 8826 } }, { "name": "Northing at false origin", "value": 0, "unit": { "type": "LinearUnit", "name": "US survey foot", "conversion_factor": 0.304800609601219 }, "id": { "authority": "EPSG", "code": 8827 } } ] }, "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": 32099 } }, "target_crs": { "type": "GeographicCRS", "name": "NAD83(CSRS)", "datum": { "type": "GeodeticReferenceFrame", "name": "NAD83 Canadian Spatial Reference System", "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": 4617 }, "remarks": "Includes all versions of NAD83(CSRS) from v2 [CSRS98] onwards without specific identification. As such it has an accuracy of approximately 1m. Note: this CRS includes longitudes which are POSITIVE EAST." }, "transformation": { "name": "NAD27 to NAD83(CSRS) (1)", "method": { "name": "NTv2", "id": { "authority": "EPSG", "code": 9615 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "QUE27-98.gsb", "id": { "authority": "EPSG", "code": 8656 } } ], "id": { "authority": "EPSG", "code": 1844 } } }
Definition: Mapnik
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