A low power city-scale wireless sensor network for the monitoring of monumental structures

In this paper the authors describe the architecture of a Wide Area Wireless Sensor Network (WSN) to be employed for the monitoring of large scale monumental structures. The proposed Sensor Network is composed by low power sensor nodes, provided with LoRa connectivity, able to measure displacements of structural cracks in buildings with a ten-micrometer degree of accuracy. Description is provided about the functioning of the displacement sensor, the structure of the sensor network node and the overall network architecture. The whole infrastructure has been designed for the monitoring of the medieval city walls in the town of Siena, where two prototypical sensor nodes have been installed and have acquired data for about one year. The proposed architecture can be applied to any context where a city scale monitoring is required. Test results are provided about the data collection and network coverage for the test site.