Abstract. Geophysical studies and real-time monitoring of natural hazards, such as volcanic eruptions or severe weather events, benefit from the joint analysis of multiple geophysical parameters. However, typical geophysical measurement platforms still provide logging solutions for a single parameter, due to different community standards and the higher cost rate per added sensor. In this work, the infrasound-logger is presented, which has been designed as a low-cost mobile multidisciplinary measurement platform for geophysical monitoring. The platform monitors in particular infrasound, but concurrently measures barometric pressure, accelerations, wind flow and uses the Global Positioning System (GPS) for positioning of the platform. Due to its digital design, the sensor platform can readily be integrated with existing geophysical data infrastructures and be embedded in the analysis of geophysical data. The small dimensions and lower cost price per unit allow for unconventional experimental designs, for example high density spatial sampling or deployment on moving measurement platforms. Moreover, such deployments can complement existing high-fidelity geophysical sensor networks. The platform is designed using digital Micro-electromechanical Systems (MEMS) sensors that are embedded on a Printed Circuit Board (PCB). The MEMS sensors on the PCB are: a GPS, a three-component accelerometer, a barometric pressure sensor, an anemometer and a differential pressure sensor. A programmable microcontroller unit controls the sampling frequency of the sensors, and the data storage. A waterproof casing is used to protect the mobile platform against the weather. The casing is created with a stereolithography (SLA) Formlabs 3D printer, using durable resin. Thanks to a low power consumption (9 Wh over 25 days), the system can be powered by a battery or solar panel. Besides the description of the platform design, we discuss the calibration and performance of the individual sensors.
Improving activity recognition using a wearable barometric pressure sensor in mobility-impaired stroke patients
