Ice detection and under-ice flow monitoring using a SonTek Argonaut-SW

The Argonaut-SW is an acoustic Doppler current meter designed for water level, velocity and flow monitoring in rivers and channels. When working in ice affected rivers, some means of determining if ice is present is required to provide accurate flow data. Using data collected with an Argonaut-SW in the Chateauguay River in Quebec, Canada in 2004, algorithms were developed that allow the Argonaut-SW to detect the presence or absence of ice on a river in real-time. These algorithms were developed using data collected during winter and ice break up in the spring of 2004. The new algorithms have been tested at a number of sites during the freeze up and winter of 2004-2005. The ice detection algorithms provide a reliable and highly efficient means of detecting ice formation on the river. The Argonaut-SW also provides reliable stage, velocity and flow data while operating under ice. Combined with the ice detection data, this allows for substantial improvement in flow monitoring on ice affected rivers. Data from a number of Argonaut-SW installations involving flow under ice conditions will be presented, both with respect to the ice detection algorithms and the overall flow monitoring capabilities.