Iceberg Detection with L-Band ALOS-2 Data Using the Dual-POL Ratio Anomaly Detector

Abstract

Icebergs represent a danger to navigation in cold waters. Detection and tracking of large icebergs using space-borne scatterometers, altimeters and synthetic aperture radar (SAR) systems have seen a large amount of work in the last decades. However, the identification of small icebergs is still challenging especially when these are embedded in sea ice. In this work, a recently proposed iceberg detector the intensity Dual-Pol Ratio Anomaly Detector (iDPolRAD) is tested using ALOS-2 L-band data. The detector is designed for dual-polarized incoherent SAR images, however in this work we want to investigate the loss of performance with respect to using coherent data. Therefore different versions of the iDPolRAD requiring quad-pol data are proposed here and tested. The ALOS-2 data were acquired on the East Coast of Greenland, where a large number of icebergs are visible in the images. The results show that different polarisations could bring different information and therefore the availability of dual-pol could improve the detection although a quad-pol algorithm will not be operational at the moment due to the limited size of the swath.