The Satellite Lab operates an automated ground station, located on the roof of Queen’s Building, that can receive and transmit data in the UHF and VHF bands. The ground station was repaired over the summer of 2023, following damage sustained to the antennas during a storm in 2019. Since then, preliminary tests on the ground station have been successful, with over 1000 frames of data being received and decoded from the FUNcube-1 satellite. The team is now working on decoding data frames from other satellites, as well as transmitting the first signals from the ground station.
The ground station consists of 70cm and 2m Wimo X-quad antennas, mounted atop a G-5500 azimuth/elevation rotator. This setup enables automated pointing of the directional antennas during a satellite pass. This offers greater signal gain compared to traditional omnidirectional antennas used by many amateur radio ground stations. Data received is passed to a Kenwood TS-2000 transceiver, where the signal is demodulated, before being digitised by a SignaLink™ for further processing and decoding.
Figure 1: Hardware for the ground station, found in the Satellite Lab 2.14 (left) and on Queen’s Building roof (right).
Software is at the heart of the ground station, indeed many future improvements to the ground station will involve migration from hardware components to software alternatives (e.g., a Software Defined Radio (SDR) in place of the TS-2000). GPredict is used to provide the pointing commands to the rotator, as well as automatic, real-time doppler compensation to the centre-frequency of the transceiver’s passband.
Decoding/encoding of data is performed using GNUradio, and the gr-satellites extension. This software provides a flowgraph representation of decoding sequences and will enable custom processing chains to be created in future, including for PROVE-Pathfinder.
As such, the ground station offers a platform for assessing the feasibility of receiving data from PROVE using a budget ground station. It is also currently being made available for use by students completing research studies as part of their undergraduate degree. The station should also be able to demonstrate live receiving of data during lectures, a useful teaching tool to bring a practical aspect space-related courses at the university.