CGQ77-98.gsb
Uses NT method which expects longitudes positive west; EPSG GeogCRSs NAD27(CGQ77) (code 4609) and NAD83(CSRS) (code 4617) have longitudes positive east. Can be taken as an approximate transformation NAD27(CGQ77) to WGS 84 - see code 1691.
Geodetic Service of Quebec. Contact alain.bernard@mrn.gouv.qc.ca
2002-07-13
Engineering survey, topographic mapping.
Replaces NAD27 / UTM zone 18N (code 26718).
Canada - Quebec - between 78°W and 72°W.
Cartesian 2D CS. Axes: easting, northing (E,N). Orientations: east, north. UoM: m.
929394.02 5981364.83
117655.86 4981667.58
1910699.01 7070669.38
-79.85 44.99
-57.1 62.62
Definition: OGC Well Known Text 2 (2019)
BOUNDCRS[ SOURCECRS[ PROJCRS["NAD27(CGQ77) / UTM zone 18N", BASEGEOGCRS["NAD27(CGQ77)", DATUM["North American Datum 1927 (CGQ77)", ELLIPSOID["Clarke 1866",6378206.4,294.978698213898, LENGTHUNIT["metre",1]]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",4609]], CONVERSION["UTM zone 18N", METHOD["Transverse Mercator", ID["EPSG",9807]], PARAMETER["Latitude of natural origin",0, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",-75, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",0.9996, SCALEUNIT["unity",1], ID["EPSG",8805]], PARAMETER["False easting",500000, LENGTHUNIT["metre",1], ID["EPSG",8806]], PARAMETER["False northing",0, LENGTHUNIT["metre",1], ID["EPSG",8807]]], CS[Cartesian,2], AXIS["(E)",east, ORDER[1], LENGTHUNIT["metre",1]], AXIS["(N)",north, ORDER[2], LENGTHUNIT["metre",1]], USAGE[ SCOPE["Engineering survey, topographic mapping."], AREA["Canada - Quebec - between 78°W and 72°W."], BBOX[44.99,-78,62.62,-72]], ID["EPSG",2032]]], 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]]], ABRIDGEDTRANSFORMATION["NAD27(CGQ77) to NAD83(CSRS) (1)", METHOD["NTv2", ID["EPSG",9615]], PARAMETERFILE["Latitude and longitude difference file","CGQ77-98.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",1845], REMARK["Uses NT method which expects longitudes positive west; EPSG GeogCRSs NAD27(CGQ77) (code 4609) and NAD83(CSRS) (code 4617) have longitudes positive east. Can be taken as an approximate transformation NAD27(CGQ77) to WGS 84 - see code 1691."]]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "BoundCRS", "source_crs": { "type": "ProjectedCRS", "name": "NAD27(CGQ77) / UTM zone 18N", "base_crs": { "name": "NAD27(CGQ77)", "datum": { "type": "GeodeticReferenceFrame", "name": "North American Datum 1927 (CGQ77)", "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": 4609 } }, "conversion": { "name": "UTM zone 18N", "method": { "name": "Transverse Mercator", "id": { "authority": "EPSG", "code": 9807 } }, "parameters": [ { "name": "Latitude of natural origin", "value": 0, "unit": "degree", "id": { "authority": "EPSG", "code": 8801 } }, { "name": "Longitude of natural origin", "value": -75, "unit": "degree", "id": { "authority": "EPSG", "code": 8802 } }, { "name": "Scale factor at natural origin", "value": 0.9996, "unit": "unity", "id": { "authority": "EPSG", "code": 8805 } }, { "name": "False easting", "value": 500000, "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": "E", "direction": "east", "unit": "metre" }, { "name": "Northing", "abbreviation": "N", "direction": "north", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 2032 } }, "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 } }, "transformation": { "name": "NAD27(CGQ77) to NAD83(CSRS) (1)", "method": { "name": "NTv2", "id": { "authority": "EPSG", "code": 9615 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "CGQ77-98.gsb", "id": { "authority": "EPSG", "code": 8656 } } ], "id": { "authority": "EPSG", "code": 1845 } } }
Definition: Mapnik
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