Oceanographic and atmospheric effects on RADARSAT-2 imagery of ship wakes

Ship wakes usually have three main elements: a Kelvin wake of gravity waves identifiable by its V-shape, a boundary layer located to a few metres around the ship and a turbulent wake which may appear as a linear disturbance behind the vessel This thesis explores the observation of ship wakes using imagery from a space based Synthetic Aperture Radar (SAR). The visibility of these wakes is highly affected by the interactions between the ship generated water movement and the wind as well as water motions associated with the ambient wave field.The visibility of the most prominent ship wake feature, the turbulent wake, is highly dependent on six components: wind speed, wind direction relative to the radar's look direction, ship's speed, ship's size, ship's course relative to the radar look direction and number of screws. Using these components, a set of rules was developed and proved to be successful in explaining turbulent wake visibility. During the course of this study, no features were seen that could be unambiguously associated with Kelvin wakes.The visibility of the turbulent wake in radar images demonstrates the potential impact on the assessment of the Recognized Maritime Picture (RMP). By The information derived by RADARSAT-2 observation of ship wakes can validate AIS data which could enhance maritime surveillance in Canada's coastal waters in the Pacific, Atlantic and the Arctic Oceans.This investigation of ship wake visibility used 13 RADARSAT-2 dual-pol (VV-VH) fine mode images of three high traffic shipping areas. These areas are: the Strait of Georgia, the approach to Halifax Harbour, and eastern Lake Ontario at the entrance of the St. Lawrence Seaway. Sixty vessels were observed over the data collection period and their wakes were analyzed. The turbulent wake was the most prominent and therefore became the focus of this thesis. Automatic Identification System (AIS) data from all three areas was used to validate RADARSAT-2 imagery by providing vessel's static and dynamic information.