Introduction¶

Nowadays, a huge need for LEO is rising. With the spreading of the Internet of Things (IoT), we need more and more Machine To Machine (M2M) communications. Those communications do not require a very high throughput, and therefore not a lot of bandwidth, but the terminal size has to be pretty small. However, this is not very convenient with GEO satellites because the losses due to the free space path loss are very high, and since LEO satellites are closer, the losses due to free space path loss are smaller. Furthemore, since M2M communication can operate on the L band (small required bandwidth), the frequency used is low, which lowers again the free space path loss. That way, less power is required in LEO to close the link budget, which means we can have smaller terminals. In this context, the aim of this project is to implement an orbit and link budget calculator for a ground station dedicated to a LEO satellite. The point is to have a ground station that could be autonomous. The program is written in LabView, since it is compatible with the antenna’s processor owned by the Telecom Bretagne Lab in ISAE campus.

This report explains how it is possible to calculate the satellite’s position and how to perform the link budget if the satellite is in sight. Thus, the state of art of orbit propagators will be presented, followed by a complete description of the Two-Lines Element (TLE). Then, the calculation of the position of the satellite with respect to the ground station (distance, elevation and azimuth) will be explained, and we will finish with the implementation of the link budget calculation.

State of Art of the Orbit Propagators
The Two-Lines Element
Distance Elevation and Azimuth Calculation
Link Budget
User Guide