NUTS - NTNU Test Satellite, a Norwegian CubeSat Project

DGSN - Distributed Ground Station Network

Written by: Gudmund Gunnarsen
Published: 04.03.15

We are now working in group 5 on programming a system that can identify call sign beacons from satellites, with the goal of establishing positions and orbit parameters. Our part of the project, which was started by Andreas Hornig of the university of Stuttgart, Germany, is to determine signals from background noise, as well as finding the equipment necessary while keeping in mind price as well as availability. This last point is important as DGSN is based on having a large array of ground stations all over the world, with individual radio amateurs contributing.

Today we have begun checking what kind of signal strength we can assume based on height, atmospheric noise and other parameters, as well as what kind of signal strength we actually need to get a coherent, sensible signal. Additionally, we have been finding the antenna's requirements, both in gain and in field of view.

Otherwise we have also begun getting a proper understanding of how to identify the signals using python with nympy/scipy and matplotlib, with deciding on how to account for effects such as doppler shift being a significant part of the discussion. 

Pictured is the radio we will be using, a low cost DVB-T software defined radio. We have also used the NTNU ground station with this radio to receive several satellite call signs, some of which were cubesats.