Geodetic CRS: NAD27
Datum: North American Datum 1927
Ellipsoid: Clarke 1866
Prime meridian: Greenwich
Data source: EPSG
Information source: US Coast & Geodetic Survey www.ngs.noaa.gov
Revision date: 2021-10-18
Scope: Transformation of coordinates at 0.2m level of accuracy.
Remarks: Uses NADCON method which expects longitudes positive west; EPSG GeogCRS NAD27 (code 4267) and NAD83 (code 4269) have longitudes positive east. For application in Gulf of Mexico refer to IOGP report 373-26.
Method: NADCON
Description: (0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["NAD27 to NAD83 (1)", VERSION["NGS-Usa Conus"], SOURCECRS[ GEOGCRS["NAD27", DATUM["North American Datum 1927", 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",4267]]], 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["NADCON", ID["EPSG",9613]], PARAMETERFILE["Latitude difference file","conus.las"], PARAMETERFILE["Longitude difference file","conus.los"], OPERATIONACCURACY[0.15], USAGE[ SCOPE["Transformation of coordinates at 0.2m level of accuracy."], AREA["United States (USA) - CONUS including EEZ - onshore and offshore - Alabama; 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. US Gulf of Mexico (GoM) OCS."], BBOX[23.81,-129.17,49.38,-65.69]], ID["EPSG",1241], REMARK["Uses NADCON method which expects longitudes positive west; EPSG GeogCRS NAD27 (code 4267) and NAD83 (code 4269) have longitudes positive east. For application in Gulf of Mexico refer to IOGP report 373-26."]]
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:1241","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=us_noaa_conus.tif +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 to NAD83 (1)", "source_crs": { "type": "GeographicCRS", "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 }, "remarks": "Note: this CRS includes longitudes which are POSITIVE EAST. Replaced by NAD27(76) (code 4608) in Ontario, CGQ77 (code 4609) in Quebec, Mexican Datum of 1993 (code 4483) in Mexico, NAD83 (code 4269) in Canada (excl. Ontario & Quebec) & USA." }, "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": "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 } } ], "accuracy": "0.15", "scope": "Transformation of coordinates at 0.2m level of accuracy.", "area": "United States (USA) - CONUS including EEZ - onshore and offshore - Alabama; 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. US Gulf of Mexico (GoM) OCS.", "bbox": { "south_latitude": 23.81, "west_longitude": -129.17, "north_latitude": 49.38, "east_longitude": -65.69 }, "id": { "authority": "EPSG", "code": 1241 }, "remarks": "Uses NADCON method which expects longitudes positive west; EPSG GeogCRS NAD27 (code 4267) and NAD83 (code 4269) have longitudes positive east. For application in Gulf of Mexico refer to IOGP report 373-26." }
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=us_noaa_conus.tif" "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=us_noaa_conus.tif +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=us_noaa_conus.tif +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 ( 1241, 'EPSG', 1241, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=us_noaa_conus.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');