The aim of this work is to verify and demonstrate the possibility of using X-band radars to identify, discriminate, characterize and follow small floating aggregations of marine litter (Small Garbage Islands—SGIs) made up mainly of plastic debris. To this end, a radar measurement campaign was carried out on a series of controlled releases into the sea of SGI modules assembled in the lab using the waste collected along a beach near the port of Livorno, in Tuscany, where the X-band radar of the Institute of Bioeconomy (IBE) of the National Research Council (CNR) is installed. The results of this first measurement campaign, which are illustrated in this preliminary work, are of interest to the entire scientific community that operates in the field of macroplastics analysis and monitoring, opening a new experimental avenue for the use of X-band radars also to monitor plastic waste at sea. Furthermore, the results obtained suggest good prospects for the use of X-band radars also for the study of coastal hydrodynamics on a local scale as well as in areas where it would be difficult to carry out measurements employing other technologies.

This paper presents an assessment of X-band radar’s detection capability to monitor Small Garbage Islands (SGIs), i.e., floating aggregations of marine litter consisting chiefly of plastic, under changing sea states. For this purpose, two radar measurement campaigns were carried out with controlled releases at sea of SGI modules assembled in the laboratory. One campaign was carried out with a calm sea and almost no wind in order to determine the X-band radar system’s detection capabilities in an ideal scenario, while the other campaign took place with rough seas and wind. An analysis of the data acquired during the campaigns confirmed that X-band radar can detect small aggregations of litter floating on the sea surface. To demonstrate the radar’s ability to detect SGIs, a statistical analysis was carried out to calculate the probability of false alarm and the probability of detection for two releases at two different distances from the radar. For greater readability of this work, all of the results obtained are presented both in terms of radar intensity and in terms of the radar cross-section relating to both the targets and the clutter. Another interesting study that is presented in this article concerns the measurement of the speed of movement (drift) of the SGIs compared with the measurement of the speed of the surface currents provided at the same time by the radar. The study also identified the radar detection limits depending on the sea state and the target distance from the antenna.

This study is to describe the activities carried on in the frame of the research project Multi-layEr approaCh to detect and analyze cOastal aggregation of MAcRo-plastic littEr (ECO-MARE). The research activity, funded by the Italian Ministry of Research (MUR), is to observe aggregation of macroplastic at sea using measurements remotely sensed by a suite of sensors equipped onboard of tower-, drone-, and satellite platforms. In this study, the design of the research activity is described and a preliminary experimental campaign will be presented.

This work show the limits of the detection capacity of X-band radars, as the sea state changes, in order to identify, discriminate, characterize and track small floating aggregations of plastic marine litter (Small Garbage Island - SGIs). Two distinct radar measurement campaigns were conducted at sea of SGI modules assembled in the laboratory. The measurement were carried out respectively in conditions of calm sea, to test the system in ideal conditions, and in rough sea conditions. The data analysis confirmed the ability of the X-band radars to detect the aggregations of floating waste on the sea surface.