One of the core competences at the department of Electronic Warfare Systems lies within the area of geolocation of radar emitters. This research activity has since 2003 been conducted within the research project "VMS i NBF". This report describes an approximate analytical method to estimate the obtainable accuracy in geolocation for a number of geolocation methods. Each method is based on the combination of two LOPs (Line Of Position). The LOP is generated from measurement of Angle Of Arrival (AOA), Time Difference Of Arrival (TDOA) or Frequency Difference Of Arrival (FDOA). The method is evaluated by comparison with results from simulations. One measure of accuracy, namely the CEP (Circular Error Probable), constitutes the basis of the comparison using both a fixed geometry and a more general case. The results show that the analytical expression can, in most cases, replace the more time-consuming simulations since these two approaches achieve comparable performance when it comes to estimation the CEP.