Cover: Observing estuarine currents and fronts in the Tay Estuary, Scotland, using an airborne SAR with along‐track interferometry (ATI)

Abstract

Estuaries are extremely dynamic environments where large and frequent changes in bathymetry and channel locations can occur. Because estuaries are major centres of population and industry, there is an ongoing requirement to monitor and predict changes in the current fields. The tidal range, surface wind speed, atmospheric pressure, fresh water inflow and most importantly the stage of the tidal cycle affect the flow vectors. Existing boat‐based methods are unable to provide measurements of current fields with sufficient spatial and depth coverage for accurate modelling of hydrodynamic processes in estuaries. Remotely sensed data offer more extensive, synoptic, spatial coverage. However, previous studies to map the full details of the current field based on conventional optical and thermal imaging have been limited by insufficient temporal coverage and the lack of identifiable features that can be tracked. Synthetic aperture radar (SAR) imaging with along‐track interferometry (ATI) has the potential to overcome both of these limitations because it can retrieve quantitative measurements of sea surface state parameters and instantaneous surface flow from a single pass over a whole estuary. The preliminary results of ATI observations over the Tay Estuary, Scotland, validated with coincident in situ boat based observations, are presented here.