In this paper, we deal with the solution of an inverse problem involving the real-time identification of a position-dependent transient heat flux, imposed on the top surface of a thin plate by a laser diode. Infrared thermography measurements of the temperature of the plate, at the same surface where the heat flux is imposed, are used in the inverse analysis. The physical problem involves two-dimensional transient heat conduction in a plate with constant thermophysical properties, initially at a uniform temperature. A partial lumping across the plate's thickness is used for the mathematical formulation of the physical problem. We use the Steady State Kalman Filter (SSKF) for the solution of the inverse problem in real-time. The Steady State Kalman Filter results are compared to those obtained with the Classical Kalman Filter (CKF), in experiments where a laser diode at the 830 nm wavelength is used to heat the samples.