An antenna tracking system adjusts the axis of an antenna to follow a moving signal source like a communication satellite. The working of an antenna tracking system is quite simple; the antenna is, first of all, commanded to move in any direction. Then, the level of the received signal is compared with the previous signal intensity. If the strength of the received signal has increased, the antenna is commanded to move in that direction. If the signal level of the received signal has gone down, the antenna moves in the opposite direction, and in this way, an antenna tracking system follows a communication satellite.
The tracking system consists of two main parts: a control part and the physical structure of the antenna. The control part is responsible for making the two-axis positions of the antenna follow a predefined trajectory during satellite tracking. There are two degrees of freedom for an antenna, namely azimuth, and the elevation angle. The elevation angle is used to define how up in the sky the antenna must face. The azimuth angle, on the other hand, tells us in which direction the antenna should face. An azimuth value ranges from 0 to 360 degrees. Here, north is 0 degrees, and when you change the antenna face to the east, it will be 90 degrees and so on. When you return to facing north, completing the rotation, it will read 360 degrees.
The elevation value ranges from 0 to 180 degrees. When the satellite is overhead, the value will be 90 degrees, and when at the horizon, the value will be 0 degrees. So, it is easy to point at the sky with the help of azimuth and elevation values.
Daniel Nikolajsen from Sweden shared his compact satellite antenna tracking device SATRAN. SATRAN is an azimuth/elevation rotator that can be controlled via an android app and can be 3D printed at home. The rotator of the project has a 3D printed mount that is compatible with many different kinds of antennas.