The Hub Optical Ground Station (HOGS)

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The Heriot-Watt campus has been selected as the site for the Hub’s state-of-the-art new optical ground station. Edinburgh City Council recently approved milestone plans for the £2.5 million telescope station at the University’s Research Park on the western outskirts of the capital.

The Heriot-Watt University Executive approved the proposal to locate the HOGS satellite base station within the Edinburgh campus following an extensive review of available locations. Being situated on the campus offers many benefits to the project including access to local lab equipment infrastructure, improved sustainability measures and ready engagement with teaching and research resources across the wider academic community at Heriot-Watt University. 

The location identified for the site has been approved by the Civil Aviation Authority (CAA) during tests over the summer of 2023 posing no barriers to operations of SPOQC. The HOGS team is currently working with colleagues in the capital projects team to prepare the site for installation in 2024. As part of the process of assessing the suitability of the site, the HOGS team have undertaken: site assessments for light pollution measurements and visits to assess groundwork/cabling/ducting; plus assessment for dark optical fibre connectivity. The resulting report has indicated that the chosen site offers ideal conditions for the station operation. 

The HOGS consists of a robotic observatory dome (Allsky 4.5m dome with base and support systems procured by BAADER) and 70cm-wide observatory reflective telescope (RC700 design with metallic coatings, procured by Planewave), used to both track the low-Earth orbit satellite path with high precision and receive the quantum signals. Adaptive optics, supported with additional EPSRC funding, will be used to further enhance the telescope capability. Both HOGS and the satellite will employ laser beacons to accurately point towards each other. Once they are precisely aligned, the quantum communications will commence. The HOGS will utilise one of two quantum receivers, dependent upon which quantum source on SPOQC is active. DV quantum signals will be measured and analysed using photon detectors. CV quantum signals will be detected and analysed, against the reference beam also sent from the satellite, using a homodyne detector. In both cases, after combination with the supporting RF communications, quantum keys can be generated.