EPSG:26771

NAD27 / Illinois East

Selected transformation

Method: NADCON

Grid Files: conus.las conus.los

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.

Information source: US Coast & Geodetic Survey www.ngs.noaa.gov

Revision date: 2021-10-18

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Definition: OGC Well Known Text 2 (2019)

BOUNDCRS[
    SOURCECRS[
        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]]],
    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 to NAD83 (1)",
        METHOD["NADCON",
            ID["EPSG",9613]],
        PARAMETERFILE["Latitude difference file","conus.las"],
        PARAMETERFILE["Longitude difference file","conus.los"],
        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: PROJ.4

+proj=tmerc +lat_0=36.6666666666667 +lon_0=-88.3333333333333 +k=0.999975 +x_0=152400.30480061 +y_0=0 +datum=NAD27 +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 +datum=NAD27 +units=us-ft +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "BoundCRS",
    "source_crs": {
        "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,
                    "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": "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
                    }
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 26771
        }
    },
    "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
        }
    }
}

Definition: MapServer - MAPfile

PROJECTION
	"proj=tmerc"
	"lat_0=36.6666666666667"
	"lon_0=-88.3333333333333"
	"k=0.999975"
	"x_0=152400.30480061"
	"y_0=0"
	"datum=NAD27"
	"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 +datum=NAD27 +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 +datum=NAD27 +units=us-ft +no_defs +type=crs">
	</Layer>
</Map>