EPSG:26771

NAD27 / Illinois East

Available transformations
to EPSG:4326

Selected transformation

Name: NAD27 to WGS 84 (79)

Method: NADCON

Grid Files: conus.las conus.los

Remarks: Parameter files are from NAD27 to NAD83 (1) (code 1241) assuming that NAD83 is equivalent to WGS 84 within the accuracy of this tfm. Uses NADCON method which expects longitudes positive west; EPSG CRS codes 4267 and 4326 have longitudes positive east.

Information source: OGP

Revision date: 2021-09-10

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Definition: OGC Well Known Text

PROJCS["NAD27 / Illinois East",
    GEOGCS["NAD27",
        DATUM["North_American_Datum_1927",
            SPHEROID["Clarke 1866",6378206.4,294.978698213898],
            EXTENSION["PROJ4_GRIDS","us_noaa_conus.tif"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4267"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",36.6666666666667],
    PARAMETER["central_meridian",-88.3333333333333],
    PARAMETER["scale_factor",0.999975],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["US survey foot",0.304800609601219],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","26771"]]

Definition: OGC Well Known Text 2 (2019)

PROJCRS["NAD27 / Illinois East",
    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["Illinois CS27 East zone",
        METHOD["Transverse Mercator",
            ID["EPSG",9807]],
        PARAMETER["Latitude of natural origin",36.6666666666667,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8801]],
        PARAMETER["Longitude of natural origin",-88.3333333333333,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8802]],
        PARAMETER["Scale factor at natural origin",0.999975,
            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]],
    USAGE[
        SCOPE["Engineering survey, topographic mapping."],
        AREA["United States (USA) - Illinois - counties of Boone; Champaign; Clark; Clay; Coles; Cook; Crawford; Cumberland; De Kalb; De Witt; Douglas; Du Page; Edgar; Edwards; Effingham; Fayette; Ford; Franklin; Gallatin; Grundy; Hamilton; Hardin; Iroquois; Jasper; Jefferson; Johnson; Kane; Kankakee; Kendall; La Salle; Lake; Lawrence; Livingston; Macon; Marion; Massac; McHenry; McLean; Moultrie; Piatt; Pope; Richland; Saline; Shelby; Vermilion; Wabash; Wayne; White; Will; Williamson."],
        BBOX[37.06,-89.27,42.5,-87.02]],
    ID["EPSG",26771]]

Definition: ESRI Well Known Text

PROJCS["NAD_1927_StatePlane_Illinois_East_FIPS_1201",
    GEOGCS["GCS_North_American_1927",
        DATUM["D_North_American_1927",
            SPHEROID["Clarke_1866",6378206.4,294.978698213898],
            EXTENSION["PROJ4_GRIDS","us_noaa_conus.tif"]],
        PRIMEM["Greenwich",0.0],
        UNIT["Degree",0.0174532925199433]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["False_Easting",500000.0],
    PARAMETER["False_Northing",0.0],
    PARAMETER["Central_Meridian",-88.3333333333333],
    PARAMETER["Scale_Factor",0.999975],
    PARAMETER["Latitude_Of_Origin",36.6666666666667],
    UNIT["US survey foot",0.304800609601219]]

Definition: PROJ.4

+proj=tmerc +lat_0=36.6666666666667 +lon_0=-88.3333333333333 +k=0.999975 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +nadgrids=us_noaa_conus.tif +units=us-ft +no_defs +type=crs

Definition: JavaScript (Proj4js)

proj4.defs("EPSG:26771","+proj=tmerc +lat_0=36.6666666666667 +lon_0=-88.3333333333333 +k=0.999975 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +nadgrids=us_noaa_conus.tif +units=us-ft +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "ProjectedCRS",
    "name": "NAD27 / Illinois East",
    "base_crs": {
        "name": "NAD27",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "North American Datum 1927",
            "ellipsoid": {
                "name": "Clarke 1866",
                "semi_major_axis": 6378206.4,
                "inverse_flattening": 294.978698213898
            }
        },
        "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": "Illinois CS27 East zone",
        "method": {
            "name": "Transverse Mercator",
            "id": {
                "authority": "EPSG",
                "code": 9807
            }
        },
        "parameters": [
            {
                "name": "Latitude of natural origin",
                "value": 36.6666666666667,
                "unit": "degree",
                "id": {
                    "authority": "EPSG",
                    "code": 8801
                }
            },
            {
                "name": "Longitude of natural origin",
                "value": -88.3333333333333,
                "unit": "degree",
                "id": {
                    "authority": "EPSG",
                    "code": 8802
                }
            },
            {
                "name": "Scale factor at natural origin",
                "value": 0.999975,
                "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
                }
            }
        ]
    },
    "scope": "Engineering survey, topographic mapping.",
    "area": "United States (USA) - Illinois - counties of Boone; Champaign; Clark; Clay; Coles; Cook; Crawford; Cumberland; De Kalb; De Witt; Douglas; Du Page; Edgar; Edwards; Effingham; Fayette; Ford; Franklin; Gallatin; Grundy; Hamilton; Hardin; Iroquois; Jasper; Jefferson; Johnson; Kane; Kankakee; Kendall; La Salle; Lake; Lawrence; Livingston; Macon; Marion; Massac; McHenry; McLean; Moultrie; Piatt; Pope; Richland; Saline; Shelby; Vermilion; Wabash; Wayne; White; Will; Williamson.",
    "bbox": {
        "south_latitude": 37.06,
        "west_longitude": -89.27,
        "north_latitude": 42.5,
        "east_longitude": -87.02
    },
    "id": {
        "authority": "EPSG",
        "code": 26771
    }
}

Definition: GeoServer

26771=PROJCS["NAD27 / Illinois East",GEOGCS["NAD27",DATUM["North_American_Datum_1927",SPHEROID["Clarke 1866",6378206.4,294.978698213898],EXTENSION["PROJ4_GRIDS","us_noaa_conus.tif"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4267"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",36.6666666666667],PARAMETER["central_meridian",-88.3333333333333],PARAMETER["scale_factor",0.999975],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["US survey foot",0.304800609601219],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","26771"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=tmerc"
	"lat_0=36.6666666666667"
	"lon_0=-88.3333333333333"
	"k=0.999975"
	"x_0=152400.30480061"
	"y_0=0"
	"ellps=clrk66"
	"nadgrids=us_noaa_conus.tif"
	"units=us-ft"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=tmerc +lat_0=36.6666666666667 +lon_0=-88.3333333333333 +k=0.999975 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +nadgrids=us_noaa_conus.tif +units=us-ft +no_defs +type=crs">
	<Layer srs="+proj=tmerc +lat_0=36.6666666666667 +lon_0=-88.3333333333333 +k=0.999975 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +nadgrids=us_noaa_conus.tif +units=us-ft +no_defs +type=crs">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 26771, 'EPSG', 26771, '+proj=tmerc +lat_0=36.6666666666667 +lon_0=-88.3333333333333 +k=0.999975 +x_0=152400.30480061 +y_0=0 +ellps=clrk66 +nadgrids=us_noaa_conus.tif +units=us-ft +no_defs +type=crs', 'PROJCS["NAD27 / Illinois East",GEOGCS["NAD27",DATUM["North_American_Datum_1927",SPHEROID["Clarke 1866",6378206.4,294.978698213898],EXTENSION["PROJ4_GRIDS","us_noaa_conus.tif"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4267"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",36.6666666666667],PARAMETER["central_meridian",-88.3333333333333],PARAMETER["scale_factor",0.999975],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["US survey foot",0.304800609601219],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","26771"]]');