metre
EPSG
US Army Map Service Technical Manual; 1943.
1999-04-22
Original Bessel definition is a=3272077.14 and b=3261139.33 toise. This used a weighted mean of values from several authors but did not account for differences in the length of the various toise: the "Bessel toise" is therefore of uncertain length.
Definition: OGC Well Known Text 2 (2019)
ELLIPSOID["Bessel 1841",6377397.155,299.1528128, LENGTHUNIT["metre",1], ID["EPSG",7004]]
Definition: ESRI Well Known Text
SPHEROID["Bessel_1841",6377397.155,299.1528128]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.5/projjson.schema.json", "type": "Ellipsoid", "name": "Bessel 1841", "semi_major_axis": 6377397.155, "inverse_flattening": 299.1528128, "id": { "authority": "EPSG", "code": 7004 } }