Real-time wave monitoring on coastal areas using LPWAN-based embedded systems

Abstract

A new embedded system is presented for real-time wave monitoring on coastal areas using SigFox communication. SigFox is a Low-Power Wide-Area Network technology that has been rarely used in coastal marine monitoring. The system is based on the low-power TD1205P module that includes a microcontroller, an accelerometer, a GNSS receiver and a SigFox transceiver. Each hour, the module estimates the wave’s maximum height (Hmax) and mean period (Tz), determines the GPS position, and wirelessly transmits the data through the SigFox network. The procedure for wave parameter estimation is based on the zero-upcrossing method using the vertical acceleration data. It was experimentally validated by attaching the embedded system to a moored buoy and comparing Hmax and Tz with that provided by a seafloor acoustic wave and current profiler, used as a reference. Results over a period of two months show a good match for Hmax but less for Tz, which cross-correlation values at zero lag of about 0.85 and 0.5, respectively. Power tests of the embedded system were also performed resulting in a lifetime estimation of 420 days with a battery pack of 3 Ah.