Research and Application on In Situ Monitoring System Based on Sensor Array for Intertidal Beach Topography

Terrain monitoring of intertidal beach is important to the coastline evolution research. Due to the complexity of the intertidal environment and the dynamics of terrain changes, in situ, real-time, and long-term monitoring of intertidal beach topography are big difficulties for existing observation methods. This article describes the design and field experimental research of a terrain in situ monitoring system based on sensor array. The monitoring system has two 20-m long flexible sensor arrays containing 42 sensor nodes can monitor the terrain changes of an area with $10\times 10$ m simultaneously. The optimal arrangement conditions of sensor arrays are deduced to completely reconstruct the terrain changes. A calculation model for terrain change is also proposed to convert the three-axis acceleration into vertical displacement of sensor array. To evaluate the monitoring system and validate the arrangement condition and reconstruction model, a field experiment is conducted on an intertidal beach in Zhoushan Island. The cumulative displacement and vertical velocity of silt zone and tidal height and waves are observed and obtained. The results demonstrate the feasibility and stability of the proposed system under real-time field monitoring conditions.