10032559CompaQTClosedCollaborative R&DISCFDetecting the world around us has long been a cornerstone of scientific research, with many sensing technologies developed for commercial use rather than purely scientific merit. For a long time, the ability to view the subterranean environment was limited to destructive exploratory techniques, but in recent years commercial remote sensors have become more widespread. However, all these non-destructive methods can be severely hindered, ground features can be obscured and vibration or electromagnetic interference can completely prevent the generation of any useful data. These issues fundamentally limit the existing technologies for construction and infrastructure monitoring due to costly excavation and site closures, which in some cases may not be possible at all. Quantum sensing techniques offer the opportunity to overcome these barriers with precision measurements of gravity. Through cold-atom interferometry the quantum nature of a rubidium atom is compared to the phase of a laser beam in a way which can detect very small changes in how the atoms fall freely in a vacuum. Changes in this free-fall can be used to determine the local gravitational acceleration and the measurement can be used to tell whether there are voids, pipes, tunnels or oil and gas reserves beneath your feet. Significant strides have been made in the world of quantum sensing; recent scientific achievements have proven atom interferometry is an invaluable tool for subsurface detection of features like buried tunnels or pipelines (doi.org/10.1038/s41586-021-04315-3). The technology to make the step to quantum sensors already exists, and has been proven in the field, however it needs commercial engineering techniques to bring it into everyday use by those without highly specialised training. This project is led by Delta-g Limited; a new quantum start-up in a unique position to take advantage of this second-generation quantum technology, with a team experienced in construction and use of quantum gravity gradiometers for field measurements and direct links to the University of Birmingham, also partnered in the project to provide scientific support from their experienced Quantum Hub. They will partner with STL, who have a successful history of guiding quantum start-ups to commercial success and taking functional prototypes from the laboratory to field instruments and will provide the expertise to take the sensor closer to market readiness. End-user expertise within the project will be achieved through an advisory board formed by representatives from companies with a direct interest in the success of a commercially available quantum gravity gradiometer.