Frame decomposition is conventionally used to perform decomposition of fields radiated by large planar apertures into a half plane, in a rigorous and stable way. An algorithm based on a spectral partitioning concept has been developed to extend frame-based Gaussian beam launching to omnidirectional and non directive sources. Frame decomposition is applied in six planes in the spectral domain, starting from the knowledge of the radiated far field, which is partitioned through a "partition of unity" procedure. This communication outlines this method, then focuses on its application and test in a real life context where initial far field data are obtained from measurements