In this paper the inverse source problem in the presence of a reflecting plane is dealt with for a two-dimensional configuration and bounded rectilinear strip sources. The cases of both orthogonal and parallel (to the reflecting plane) sources are considered. Analytical arguments are developed to estimate the singular value decomposition of the pertinent radiation operator. This allows highlighting of the role played by the reflecting plane in the so-called number of degrees of freedom of the radiated field as well as in the achievable resolution while reconstructing the unknown sources.