This paper implements an open-loop controller for generating the earth’s magnetic field in the vessel’s coordinate frame. It also incorporates the rotational movements along the three axes, without physically moving the object. This has a potential application in the prediction of signature for ferromagnetic marine vessels in changing the earth’s magnetic field experienced by the vessel due to change in location. It also considers the effect of the roll, pitch, and heading changes. The Uniform magnetic field simulator is designed to generate the required magnetic field in the vessel’s coordinate frame. Simulation results are verified using an experimental laboratory setup.