SIRGAS 2000 in UTM zone 23S
EPSG:31983 is SIRGAS 2000 / UTM zone 23S, a Transverse Mercator projection in metres on the GRS80 ellipsoid. Its central meridian is 45° W, the latitude of origin is 0°, the scale factor is 0.9996, the false easting is 500,000 m and the false northing is 10,000,000 m.
The definition bundled with mapverter gives an area of use from 48° to 42° W and 33.5° S to 5.13° N. On the central meridian x is exactly 500,000 m: the point at 45° W, 15° S, for example, is x = 500,000 m and y = 8,341,674 m.
Zone and hemisphere
The S in the name marks the southern UTM convention with a false northing of 10,000,000 m. The definition applies it to the whole recorded area, including the part north of the equator, where northings exceed 10,000,000 m. Confirm the actual code rather than inferring the hemisphere from a label alone.
How mapverter handles EPSG:31983
- A .prj is matched by its EPSG code or by its projection parameters, so ESRI-style names such as SIRGAS_2000_UTM_Zone_23S are recognized as well.
- Without a .prj, the Portuguese interface offers EPSG:31983 first among the candidates that fit the data, ahead of zones 22S, 24S and 25S, which it also lists as target presets. The English interface does not suggest it, so search for 31983 by EPSG code in the coordinate system picker and check the result on the map.
- This page presets EPSG:31983 as the target for SHP and CSV output. KML, KMZ, GeoJSON and GPX always use WGS 84.
- For geographic SIRGAS 2000 coordinates in degrees, see EPSG:4674.