NTv1_0.gsb
Approximation at the +/- 1m level assuming that NAD83 is equivalent to WGS 84. Superseded by NAD27 to WGS 84 (27) (code 8404) in Quebec and NAD27 to WGS 84 (26) (code 8245) elsewhere in Canada.
OGP
1998-11-11
Engineering survey, topographic mapping.
United States (USA) - Alaska - between 144°W and 141°W, onshore.
Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: ftUS.
8442848.01 6507616.57
550475.75 -1759019.25
737336.99 10270972.56
-141.01 38.21
-40.73 86.46
Definition: OGC Well Known Text 2 (2019)
BOUNDCRS[ SOURCECRS[ BOUNDCRS[ SOURCECRS[ PROJCRS["NAD27 / Alaska zone 2", 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["Alaska CS27 zone 2", METHOD["Transverse Mercator", ID["EPSG",9807]], PARAMETER["Latitude of natural origin",54, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",-142, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",0.9999, SCALEUNIT["unity",1], ID["EPSG",8805]], PARAMETER["False easting",500000, LENGTHUNIT["US survey foot",0.304800609601219], ID["EPSG",8806]], PARAMETER["False northing",0, LENGTHUNIT["US survey foot",0.304800609601219], ID["EPSG",8807]]], 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]], ID["EPSG",26732]]], 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]]], ABRIDGEDTRANSFORMATION["NAD27 to NAD83 (3)", METHOD["NTv1", ID["EPSG",9614]], PARAMETERFILE["Latitude and longitude difference file","NTv1_0.gsb"], ID["EPSG",1312]]]], 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)"], 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["NAD83 to WGS 84 (1)", METHOD["Geocentric translations (geog2D domain)", ID["EPSG",9603]], PARAMETER["X-axis translation",0, ID["EPSG",8605]], PARAMETER["Y-axis translation",0, ID["EPSG",8606]], PARAMETER["Z-axis translation",0, ID["EPSG",8607]], USAGE[ SCOPE["Military survey."], 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. United States (USA) - Alabama; Alaska (mainland); Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; 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."], BBOX[23.81,-172.54,86.46,-47.74]], ID["EPSG",1188], REMARK["Derived at 354 stations. Accuracy 2m in each axis."]]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "BoundCRS", "source_crs": { "type": "BoundCRS", "source_crs": { "type": "ProjectedCRS", "name": "NAD27 / Alaska zone 2", "base_crs": { "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 } }, "conversion": { "name": "Alaska CS27 zone 2", "method": { "name": "Transverse Mercator", "id": { "authority": "EPSG", "code": 9807 } }, "parameters": [ { "name": "Latitude of natural origin", "value": 54, "unit": "degree", "id": { "authority": "EPSG", "code": 8801 } }, { "name": "Longitude of natural origin", "value": -142, "unit": "degree", "id": { "authority": "EPSG", "code": 8802 } }, { "name": "Scale factor at natural origin", "value": 0.9999, "unit": "unity", "id": { "authority": "EPSG", "code": 8805 } }, { "name": "False easting", "value": 500000, "unit": { "type": "LinearUnit", "name": "US survey foot", "conversion_factor": 0.304800609601219 }, "id": { "authority": "EPSG", "code": 8806 } }, { "name": "False northing", "value": 0, "unit": { "type": "LinearUnit", "name": "US survey foot", "conversion_factor": 0.304800609601219 }, "id": { "authority": "EPSG", "code": 8807 } } ] }, "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": 26732 } }, "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 to NAD83 (3)", "method": { "name": "NTv1", "id": { "authority": "EPSG", "code": 9614 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "NTv1_0.gsb", "id": { "authority": "EPSG", "code": 8656 } } ], "id": { "authority": "EPSG", "code": 1312 } } }, "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 } } ], "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": "NAD83 to WGS 84 (1)", "source_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 } }, "method": { "name": "Geocentric translations (geog2D domain)", "id": { "authority": "EPSG", "code": 9603 } }, "parameters": [ { "name": "X-axis translation", "value": 0, "unit": "metre", "id": { "authority": "EPSG", "code": 8605 } }, { "name": "Y-axis translation", "value": 0, "unit": "metre", "id": { "authority": "EPSG", "code": 8606 } }, { "name": "Z-axis translation", "value": 0, "unit": "metre", "id": { "authority": "EPSG", "code": 8607 } } ], "id": { "authority": "EPSG", "code": 1188 } } }
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=tmerc +lat_0=54 +lon_0=-142 +k=0.9999 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +towgs84=0,0,0,0,0,0,0 +units=us-ft +no_defs +type=crs"> <Layer srs="+proj=tmerc +lat_0=54 +lon_0=-142 +k=0.9999 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +towgs84=0,0,0,0,0,0,0 +units=us-ft +no_defs +type=crs"> </Layer> </Map>