The EPSG code of the coordinate system that all datasets in cmapgeo have been
projected in -- specifically, Illinois State Plane East (NAD83, ft). It can
be used as the crs parameter in sf::st_transform() to reproject other
sf objects that have a different projection.
cmap_crsAn object of class numeric of length 1.
if (FALSE) {
# Reproject any other sf object to match cmapgeo coordinate system
my_sf_data <- sf::st_transform(my_sf_data, crs = cmap_crs)
}
# View projection specification
sf::st_crs(cmap_crs)
#> Coordinate Reference System:
#> User input: EPSG:3435
#> wkt:
#> PROJCRS["NAD83 / Illinois East (ftUS)",
#> BASEGEOGCRS["NAD83",
#> DATUM["North American Datum 1983",
#> ELLIPSOID["GRS 1980",6378137,298.257222101,
#> LENGTHUNIT["metre",1]]],
#> PRIMEM["Greenwich",0,
#> ANGLEUNIT["degree",0.0174532925199433]],
#> ID["EPSG",4269]],
#> CONVERSION["SPCS83 Illinois East zone (US Survey feet)",
#> 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",984250,
#> 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,-89.28,42.5,-87.02]],
#> ID["EPSG",3435]]