conus.las conus.los wmhpgn.las wmhpgn.los
May be taken as approximate transformation NAD27 to WGS 84 - see code 8612.
US Coast & Geodetic Survey www.ngs.noaa.gov NADCON readme file
1999-10-20
metre
EPSG
United States Geological Survey, Western Geographic Science Center
2020-03-26
Statistical analysis.
Uses spherical projection formulas. USGS documentation describes sphere as derived from GRS80/WGS 84 ellipsoid but that actually used is Clarke 1866. For 1:1million and smaller scale maps there is no significant difference.
United States (USA) - onshore and offshore.
Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: m.
inf inf
-1292596.93 372820.14
-1245718.44 581674.83
-117.24 41.99
-113.0 49.01
Definition: OGC Well Known Text 2 (2019)
BOUNDCRS[ SOURCECRS[ BOUNDCRS[ SOURCECRS[ PROJCRS["NAD27 / US National Atlas Equal Area", 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["US National Atlas Equal Area", METHOD["Lambert Azimuthal Equal Area (Spherical)", ID["EPSG",1027]], PARAMETER["Latitude of natural origin",45, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",-100, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8802]], PARAMETER["False easting",0, LENGTHUNIT["metre",1], ID["EPSG",8806]], PARAMETER["False northing",0, LENGTHUNIT["metre",1], ID["EPSG",8807]]], CS[Cartesian,2], AXIS["easting (X)",east, ORDER[1], LENGTHUNIT["metre",1]], AXIS["northing (Y)",north, ORDER[2], LENGTHUNIT["metre",1]], ID["EPSG",9311]]], 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 (1)", METHOD["NADCON", ID["EPSG",9613]], PARAMETERFILE["Latitude difference file","conus.las"], PARAMETERFILE["Longitude difference file","conus.los"], ID["EPSG",1241]]]], TARGETCRS[ GEOGCRS["NAD83(HARN)", DATUM["NAD83 (High Accuracy Reference Network)", 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["American Samoa - onshore - Tutuila, Aunu'u, Ofu, Olesega, Ta'u and Rose islands. Guam - onshore. Northern Mariana Islands - onshore. Puerto Rico - onshore. United States (USA) - onshore 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 and Wyoming; offshore Gulf of Mexico continental shelf (GoM OCS). US Virgin Islands - onshore."], BBOX[-14.59,144.58,71.4,-64.51]], ID["EPSG",4152]]], ABRIDGEDTRANSFORMATION["NAD83 to NAD83(HARN) (9)", METHOD["NADCON", ID["EPSG",9613]], PARAMETERFILE["Latitude difference file","wmhpgn.las"], PARAMETERFILE["Longitude difference file","wmhpgn.los"], USAGE[ SCOPE["Geodesy."], AREA["United States (USA) - Idaho and Montana - west of 113°W."], BBOX[41.99,-117.24,49.01,-113]], ID["EPSG",1482], REMARK["Accuracy 67% confidence level. Uses NADCON method which expects longitudes positive west; EPSG GeogCRSs NAD83 (code 4269) and NAD83(HARN) (code 4152) have longitudes positive east. May be taken as approximate transformation NAD83-WGS 84 - see code 1716."]]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "BoundCRS", "source_crs": { "type": "BoundCRS", "source_crs": { "type": "ProjectedCRS", "name": "NAD27 / US National Atlas Equal Area", "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": "US National Atlas Equal Area", "method": { "name": "Lambert Azimuthal Equal Area (Spherical)", "id": { "authority": "EPSG", "code": 1027 } }, "parameters": [ { "name": "Latitude of natural origin", "value": 45, "unit": "degree", "id": { "authority": "EPSG", "code": 8801 } }, { "name": "Longitude of natural origin", "value": -100, "unit": "degree", "id": { "authority": "EPSG", "code": 8802 } }, { "name": "False easting", "value": 0, "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": "X", "direction": "east", "unit": "metre" }, { "name": "Northing", "abbreviation": "Y", "direction": "north", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 9311 } }, "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 (1)", "method": { "name": "NADCON", "id": { "authority": "EPSG", "code": 9613 } }, "parameters": [ { "name": "Latitude difference file", "value": "conus.las", "id": { "authority": "EPSG", "code": 8657 } }, { "name": "Longitude difference file", "value": "conus.los", "id": { "authority": "EPSG", "code": 8658 } } ], "id": { "authority": "EPSG", "code": 1241 } } }, "target_crs": { "type": "GeographicCRS", "name": "NAD83(HARN)", "datum": { "type": "GeodeticReferenceFrame", "name": "NAD83 (High Accuracy Reference Network)", "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": 4152 } }, "transformation": { "name": "NAD83 to NAD83(HARN) (9)", "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": "NADCON", "id": { "authority": "EPSG", "code": 9613 } }, "parameters": [ { "name": "Latitude difference file", "value": "wmhpgn.las", "id": { "authority": "EPSG", "code": 8657 } }, { "name": "Longitude difference file", "value": "wmhpgn.los", "id": { "authority": "EPSG", "code": 8658 } } ], "id": { "authority": "EPSG", "code": 1482 } } }
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +datum=NAD27 +units=m +no_defs +type=crs"> <Layer srs="+proj=laea +R_A +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +datum=NAD27 +units=m +no_defs +type=crs"> </Layer> </Map>