Assessment of Maritime Vessel Detection and Tracking Using Integrated SAR Imagery and AIS/V-Pass Data

Many operationally available satellite X-band SAR missions (TerraSAR-X, Kompsat-5, and COSMO-SkyMed) and new missions based on microsatellite constellations in X-band SAR (ICEYE and Capella) have dramatically increased maritime monitoring capabilities with shorter revisit times. Vessel detection in constellated SAR images has been based on various detection algorithms. AIS has been widely used to match the positions of vessels detected by SAR and identify dark vessels. However, the quality assessment of small-vessel detection has rarely been studied, and the requirements for additional monitoring data to supplement AIS have not been qualified in conjunction with vessels detected by SAR. In this study, the possibility of tracking vessels based on the constellation of SAR images was tested using an integrated field survey designed to capture small-vessel operations during SAR image acquisition from the constellations of Kompsat-5, TerraSAR-X, and Capella. The movement of ships with length of 10 m and 20 m could be estimated if the ships are commonly detected in SAR images within a short time difference. The necessity of the V-pass as additional monitoring data to supplement the AIS was quantitatively tested by comparing the matching rates of ships detected in SAR and AIS with and without the V-pass. When the V-pass data were added to the AIS, the number of vessels for the ground truth within the SAR image boundary increased and the false alarms were decreased. In the near future, the combined use of a vessel monitoring system and the integration of increasing constellations of X-band SAR images will help fill data gaps for marine monitoring, including illegal fishing vessels and marine oil spills.