May76v20.gsb
Uses NT method which expects longitudes positive west; EPSG GeogCRSs NAD27(76) (code 4608) and NAD83 (code 4269) have longitudes positive east. May be taken as approximate transformation NAD27(76) to WGS 84 - see code 1690.
Geodetic Survey of Canada http://www.geod.nrcan.gc.ca/
2019-09-17
Geodesy.
Note: this CRS includes longitudes which are POSITIVE EAST.
Ellipsoidal 2D CS. Axes: latitude, longitude. Orientations: north, east. UoM: degree
Definition: OGC Well Known Text 2 (2019)
BOUNDCRS[ SOURCECRS[ GEOGCRS["NAD27(76)", DATUM["North American Datum 1927 (1976)", 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]], USAGE[ SCOPE["Geodesy."], AREA["Canada - Ontario."], BBOX[41.67,-95.16,56.9,-74.35]], ID["EPSG",4608]]], 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]], USAGE[ SCOPE["Geodesy."], AREA["North America - onshore and offshore: Canada - Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Northwest Territories; Nova Scotia; Nunavut; Ontario; Prince Edward Island; Quebec; Saskatchewan; Yukon. Puerto Rico. United States (USA) - Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming. US Virgin Islands. British Virgin Islands."], BBOX[14.92,167.65,86.45,-40.73]], ID["EPSG",4269]]], ABRIDGEDTRANSFORMATION["NAD27(76) to NAD83 (1)", METHOD["NTv2", ID["EPSG",9615]], PARAMETERFILE["Latitude and longitude difference file","May76v20.gsb"], USAGE[ SCOPE["Not known."], AREA["Canada - Ontario."], BBOX[41.67,-95.16,56.9,-74.35]], ID["EPSG",1463], REMARK["Uses NT method which expects longitudes positive west; EPSG GeogCRSs NAD27(76) (code 4608) and NAD83 (code 4269) have longitudes positive east. May be taken as approximate transformation NAD27(76) to WGS 84 - see code 1690."]]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "BoundCRS", "source_crs": { "type": "GeographicCRS", "name": "NAD27(76)", "datum": { "type": "GeodeticReferenceFrame", "name": "North American Datum 1927 (1976)", "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": 4608 } }, "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 } }, "transformation": { "name": "NAD27(76) to NAD83 (1)", "method": { "name": "NTv2", "id": { "authority": "EPSG", "code": 9615 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "May76v20.gsb", "id": { "authority": "EPSG", "code": 8656 } } ], "id": { "authority": "EPSG", "code": 1463 } } }
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=longlat +ellps=clrk66 +no_defs +type=crs"> <Layer srs="+proj=longlat +ellps=clrk66 +no_defs +type=crs"> </Layer> </Map>