Remote video monitoring for offshore sea farms: Reliability and availability evaluation and image quality assessment via laboratory tests

In this article, the availability and reliability of a remote video monitoring system for offshore sea farming plants are studied and tested in laboratory. The scope of the system is to ensure a video surveillance infrastructure so to supervise breeding cages along with the fish inside them, in order to contrast undesired phenomena like fish poaching as well as cages damages. The system is installed on a cage floating structure: it is mainly composed of an IP camera that is controlled by a Raspberry Pi Zero which is the core of the system. Images are streamed thanks to a 3G/4G dongle, while the overall system is powered via two photovoltaic panels charging a backup battery. Simulations are carried out considering two seasonal functioning periods (i.e., winter and summer): each of them is characterised by temperature trends defined according to the average temperatures of the system deployment site, 8 km offshore the city of Piombino, Italy. In order to optimise power consumption without hindering application scenario requirements, the system operates according to a duty cycle of 2 minutes out of 15 (i.e., 8 minutes of operation per hour). The performances of the system are then tested in laboratory exploiting a climatic chamber so to simulate different environmental conditions: variations on image quality are then analysed in order to identify possible dependencies on critical situations related to specific temperature and relative humidity values and to the presence of salt in the air.