Geodetic CRS: NAD27(CGQ77)
Datum: North American Datum 1927 (CGQ77)
Ellipsoid: Clarke 1866
Prime meridian: Greenwich
Data source: EPSG
Information source: Geodetic Service of Quebec. Contact alain.bernard@mrn.gouv.qc.ca
Revision date: 2017-10-16
Scope: Historic record only - now superseded - see remarks.
Remarks: Replaced by NAD27(CGQ77) to NAD83 (2) (code 1575). Uses NT method which expects longitudes positive west; EPSG GeogCRSs CGQ77 (code 4609) and NAD83 (code 4269) have longitudes positive east.
Method: NTv1
Area of use: Canada - Quebec.
Description: (0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["NAD27(CGQ77) to NAD83 (1)", VERSION["SGQ-Can QC NT1"], SOURCECRS[ GEOGCRS["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]], 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]], ID["EPSG",4609]]], 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]], ID["EPSG",4269]]], METHOD["NTv1", ID["EPSG",9614]], PARAMETERFILE["Latitude and longitude difference file","PQV4.DAC"], OPERATIONACCURACY[1.0], USAGE[ SCOPE["Historic record only - now superseded - see remarks."], AREA["Canada - Quebec."], BBOX[44.99,-79.85,62.62,-57.1]], ID["EPSG",1451], REMARK["Replaced by NAD27(CGQ77) to NAD83 (2) (code 1575). Uses NT method which expects longitudes positive west; EPSG GeogCRSs CGQ77 (code 4609) and NAD83 (code 4269) have longitudes positive east."]]
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:1451","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=PQV4.DAC +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "Transformation", "name": "NAD27(CGQ77) to NAD83 (1)", "source_crs": { "type": "GeographicCRS", "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 }, "remarks": "Note: this CRS includes longitudes which are POSITIVE EAST." }, "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 }, "remarks": "Longitude is POSITIVE EAST. The adjustment included connections to Greenland and Mexico but the system was not adopted there. For applications with an accuracy of better than 1m replaced by NAD83(HARN) in the US and PRVI and by NAD83(CSRS) in Canada." }, "method": { "name": "NTv1", "id": { "authority": "EPSG", "code": 9614 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "PQV4.DAC", "id": { "authority": "EPSG", "code": 8656 } } ], "accuracy": "1.0", "scope": "Historic record only - now superseded - see remarks.", "area": "Canada - Quebec.", "bbox": { "south_latitude": 44.99, "west_longitude": -79.85, "north_latitude": 62.62, "east_longitude": -57.1 }, "id": { "authority": "EPSG", "code": 1451 }, "remarks": "Replaced by NAD27(CGQ77) to NAD83 (2) (code 1575). Uses NT method which expects longitudes positive west; EPSG GeogCRSs CGQ77 (code 4609) and NAD83 (code 4269) have longitudes positive east." }
Definition: MapServer - MAPfile
PROJECTION "proj=pipeline" "step" "proj=axisswap" "order=2,1" "step" "proj=unitconvert" "xy_in=deg" "xy_out=rad" "step" "proj=hgridshift" "grids=PQV4.DAC" "step" "proj=unitconvert" "xy_in=rad" "xy_out=deg" "step" "proj=axisswap" "order=2,1" END
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=PQV4.DAC +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> <Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=PQV4.DAC +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> </Layer> </Map>
Definition: SQL (PostGIS)
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 1451, 'EPSG', 1451, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=PQV4.DAC +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');