Analyzing the Situational and Event-Dependent Maritime Traffic Variations Using COSMO-SkyMed SAR Imagery in Wuhan, China, Before and During COVID-19 Lockdown

Abstract

Vessel detection and their activities in the sea can provide updates on latest trends in maritime trade. Space-borne synthetic aperture radar (SAR) can aid in detecting vessels in (almost) all weather conditions. In this study high resolution SAR data are used to analyze the maritime traffic activities, especially the underscored independency in transport trends in Wuhan, the major port-hub on the central Yangtze river in China, before and during the COVID-19 pandemic. Time-series of COSMO-SkyMed SAR images covering Wuhan from 2018 to 2020 were exploited to detect vessels. We applied multi-mode feature and shape (MMFS) image enhancement for fast and accurate vessel detection. Variations in number of vessels were detected, especially a huge drop was observed during the COVID-19 lockdown. HwkEye360 radio frequency monitoring data were used to validate our results.