Method for electronic beam direction finding in satellite communication hybrid tracking system

A method for electronic beam direction finding in a satellite communication hybrid tracking system, executed when an antenna of a user terminal (UT) and a target satellite in orbit are in relative motion, the method comprising:

• performing a pure mechanical tracking mode and a hybrid tracking mode;
• wherein the pure mechanical tracking mode is performed using a mechanical triple-axis shaft with a fixed phase to obtain an antenna broadside direction ({circumflex over (θ)}o, {circumflex over (φ)}o), wherein ({circumflex over (θ)}o, {circumflex over (φ)}o)=({circumflex over (θ)}m, {circumflex over (φ)}m)≡(π/2, 0);
• the hybrid tracking mode initially performs a coarse tracking over a large tracking scope by a one-step mechanical adjustment, and subsequently performs a fine tracking within a small tracking scope by an electrical adjustment;
• the mechanical adjustment aligns the antenna broadside direction by adjusting a bearing angle, an elevation angle, and a slant angle of the antenna using the mechanical triple-axis shaft, and the electrical adjustment fine-tunes a beam direction using a uniform planar array of a phased array antenna;
• and
• an updated beam direction is calculated in a local coordinate system based on an attitude of the antenna and a relative direction of the target satellite so as to maintain alignment between the antenna broadside direction and an incoming path direction of the target satellite.