Abstract: The tracking signals of a monopulse satellite tracking system are optimized by aligning the phases of the azimuth and elevation channels (the "difference" channels) with the reference (or "sum") channel using an autophase controller and a simulated far field source in the near field. The autophase controller monitors the output of the tracking receiver and adjusts phase shifters along the transmission paths of the azimuth and elevation channels, in a manner to maximize the outputs of the receiver. The simulated far field source provides an alignment signal for the autophase controller. The simulated far field source consists of a signal generator, a near field probe, and near field phase compensators. The probe is positioned to avoid any nulls in the simulated tracking signal for the frequencies of interest. The probe is also positioned to limit the range of the phase shifts introduced by near field placement, for the frequencies of interest.