E-USOC Intranet


Ground Station

E-USOC has a ground station for the tracking of amateur and educational satellites. This station was acquired for educational purposes. Its main objective is to offer internships and final degree projects related to satellites.

A high proportion of amateur satellites operate in the following frequency bands: 144-146 MHz, 435-438 MHz and 1260-1270 MHz. This satellites usually publish their frequencies, allowing the amateur radio community to listen and download data from the satellite.

Having the support and availability of amateur radio stations around the world is a significant advantage for some missions, as the area of coverage between the satellite and land is significantly expanded. This allows the downloading of a larger quantity of data that otherwise wouldn’t be possible with a finite number of ground stations assigned to the mission.


The ground station is composed of the set of antennas, rotor, radio and computer.  The antennas chosen are directional, “Yagi” type and have circular polarisation, UHF and VHF respectively. These antennas perform well in satellite operations. They are connected to a LNA (Low Noise Amplifier) with 10-20 dB of gain, and mounted on a fiberglass mast. An ICOM IC 910H radio is responsible for demodulation tasks at reception for the UHF y VHF frequencies, supplying the required power and modulation for transmission of commands.

In order to establish the radio link with directional “Yagi” type antenna it is necessary to use rotors to position and direct them, thus effective satellite tracking can be carried out. The computer must be equipped with a controller that can be handled automatically by software. In this way the tracking is reliable and comfortable for the user.


These devices have been tested to receive telemetry from some educational satellites with different frequencies and modulations -AFSK, BPSK, FSK 9600 bps under the standard G3RUH. They have been part of the active download of the SwissCube mission and in the download of telemetry from the precursor satellites to the QB50 mission.

The station was designed and is used for educational purposes as well. Real time telemetry reading applications have been made possible on the satellite and tracking applications are being developed. Overall, there were two final degree projects done by the Escuela Técnica Superior de Ingenieros Aeronáuticos, one done by the Escuela Técnica Superior de Ingeniería Aeronáutica y del Espacio (ETSIAE) and one by an exchange student from Scotland.

The Association of Small Satellite Tracking is responsible for operating the station under the callsign EA4RCN and it is prepared to support the Qbito mission, the first CubeSat entirely developed by the Polytechnic University of Madrid.  

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