Patent ID: 8339307

Claim:
A method for adjusting the pointing direction of a beam provided by an antenna system of a spacecraft, the spacecraft forming part of a system that includes ground stations communicating with the antenna system of the spacecraft using uplink signals and downlink signals, each in a respective frequency channel, the antenna system including a receive antenna having a plurality of antenna elements arranged in an array, each element providing a respective antenna element signal and at least one of said uplink signals including a beacon signal, the method comprising: digitising each said antenna element signal from said receive antenna, and processing each digitised antenna element signal to separate uplink signal components in respective frequency channels present in the element signal; digitally weighting, with respective beam-pointing error weight values, components of said beacon signal present in at least some of the receive antenna element signals, and assessing such weighted beacon signal components to derive a beam-pointing error signal; and employing said error signal to adjust the pointing direction of at least one communications signal beam provided by said antenna system.