An inversion algorithm based on mid-latitude magnetic data has been developed for estimation of the intensity and longitudinal distribution of the substorm current wedge (SCW), partial ring current (DRP) and symmetric Ring Current (DR) during substorms. Here we summarize some past results of testing this algorithm and show how the longitudinal range of the SCW corresponds to the dipolarizations and particle . injections observed at geostationary orbit. We conclude that in its present form the inversion algorithm is capable of obtaining the intensity as well as the longitudinal boundaries of the substorm current wedge (in the latter case with an accuracy better than 0.5 h MLT).