This report describes work in progress in the FOI project Signature Management (Signaturhantering) towards development of a computational tool for modelling and analysis of measurements of the acoustic target strength (TS) of a submarine at a shallow-water site. The purpose of such a computational tool is to support planning and configuration of TS measurement campaigns as well as post-trial analysis of data from such campaigns including, in particular, identification and elimination of environmental influences on the measurement results. An overview of the current capabilities of the modelling tool is presented and illustrated by examples from pre-trial studies of a TS measurement campaign in Horsfjärden in May 2010.