This final report for the "Signature modeling project" presents the purpose, goal, benefit, activities carried out and results achieved during the project three years. The project has included activities concerning radar as well as infrared signatures. The long-term goal of these activities is to create the ability to calculate or otherwise produce radar and infrared signature data for arbitrary objects (e.g. ships or ground vehicles) in realistic settings/conditions/backgrounds/environments/theatres. During this three year period of the project the goal has been to develop or find tools for the calculation of target-background interactions. A new method, "The Potential Method", for the calculation of objects with metallic surfaces has been derived and developed further. The virtue of this method is that it has the potential to tackle larger problems or do faster calculations than similar established methods, like the method of moments (MoM). The method has been presented at a number of conferences. The calculation method iterative physical optics (IPO) has been developed further. The benefits claimed for this method is that it is fast compared to more "exact" methods, while modelling internal multipath contributions more accurately than PO-GO. In order to correctly calculate the radar return from a craft, e.g. a battle tank in terrain, the interaction of the object with its environment needs to be taken into account. For this the bistatic reflectivity of rough surfaces (the terrain) is needed. The integral equation method is a fast method for calculating the average reflectivity of rough model surfaces, which we have evaluated and developed further. The work includes bistatic measurements on rough surfaces and for this purpose new measurement and calibration procedures have been developed. Validation of IEM has been a major task in the Swedish-French bilateral cooperation. The project has also studied if visualisation/animation sea surface models can be modified for calculation of radar sea clutter. In the infrared modelling activity area different thermal modelling program codes have been evaluated against measurements done under varying weather conditions on a simple generic object, called CUBI. The work also includes characterisation of the optical reflectance properties of the paint use on CUBI. The purpose of the validation work has been to gain know-how on the capabilities, limitations, advantages and disadvantages and best areas of application for the different thermal modelling programs.