Infra-AUV Project – Provision of measurement traceability for sound and vibration measurements in the very low frequency range.

Metrology – the science of measurement – has an important role in all fields of science and technology. Core concepts of measurement traceability and measurement uncertainty are vital for measurements to be physically meaningful and for data to be quantified with known levels of confidence. Metrology considerations begin with primary measurement standards; the definitive realisation of a particular quantity that underpins all subsequent measurements of that quantity. Primary standards for sound pressure and acceleration have long been established but historically, have not extend to the relevant frequency ranges in many geophysical applications utilizing seismic, infrasonic, and hydroacoustic technologies, including IMS applications. A European research project called Infra-AUV has recently developed new primary measurement standards for infrasound and for low-frequency seismic measurements, as well as the means to transfer these to enable the calibration of sensors in the field, as required at stations in the IMS network. New calibration capabilities and application-focussed case studies emerging from the Infra-AUV project will therefore be presented, together with the potential consequences and benefits for users of such sensor systems.