Robust Satellite Techniques for Detecting and Monitoring Icebergs by Sentinel-2 Data

In recent decades, the sharp rise in global temperatures has accelerated the melting of the polar ice caps, causing icebergs to break off and subsequently drift across the sea surface. At the same time, the increase in navigable areas in the Arctic region has led to a continued growth in maritime traffic at higher latitudes, resulting in a consequent increase in the risk of iceberg–ship collisions. In this context, it is particularly important to provide vessels at sea with timely and up-to-date information on the presence of icebergs along routes in mid- and high-latitude waters. Given this challenge, this paper presents, for the first time, the Robust Satellite Techniques (RST) methodology employed at the global level to perform iceberg detection using imagery acquired only in the B3 band (centred at 560 nm) by the Sentinel-2 (S2) constellation. A test performed near Greenland (in September 2016) and in the Labrador Sea (in August 2021), showed that, in comparison with traditional fixed-threshold methods, this approach (easily implementable in the Google Earth Engine cloud platform) demonstrated: (a) very high sensitivity by doubling the number of detected icebergs (including the smaller ones); (b) high reliability with an overall false positive below 20% that becomes zero when other objects that may pose a hazard to navigation (e.g., dark ships, shallow reefs, etc.) are also considered.