The ground segment – the UHF/VHF station

The UVSQ/LATMOS ground station (Figure 5) has been implemented, using the hardware components recommended by the INSPIRE program.
The antenna rig consists of two circular polarized Yagi antennas and two rotators, which make it possible to change the elevation and azimuth angles. The antennas are frequency centered on VHF band (for uplink from ground to space) and UHF band (for downlink from space to ground). The antenna rig is located on the roof of the Observatoire de Versailles Saint-Quentin-en-Yvelines (OVSQ) building, which offers a clear full sky for satellite visibility. The TS2000 radio is used to transmit RF signals, and a RTL-SDR radio is used to receive RF signals. The hardware (i.e. rotators and radio) is controlled through SatPC32 and SDR-Sharp software. Based on the two line elements (TLE), the SatPC32 program allows automatic tracking of the satellite and 
compensation of the Doppler shift in the radio signal. On the RF transmit line, modulation and AX.25 encapsulation are performed by hardware (i.e. TS2000), whereas de-modulation and AX.25 de-encapsulation are done by software on the RF receiver line (i.e. RTL-SDR). A custom application is employed to write and read the Consultative Committee for Space Data Systems packet utilisation standard (CCSDS PUS) protocol as well as provide a graphical user interface (GUI) to the ground station operator.
Since the UVSQ-SAT CubeSat will use satellite amateur radio frequency bands, an international frequency coordination is under preparation for being submitted to the International Amateur Radio Union. This will ensure that frequencies are not used by other satellites during UVSQ-SAT mission, and it will act as an engagement with the amateur radio community. The preparation of the frequency coordination is done with the help of the local Radio-Club (F6KRK) and the AMSAT-Francophone. Thanks to this cooperation, UVSQ-SAT will be able to transmit periodical beacon data which will be recorded over the world by amateur radio stations.

The mission center

Work in progress