Estimation of vector surface currents beyond the region of overlap of dual-site HF radar: An implementation of the continuity equation

When two or more radars illuminate the same area of ocean it is possible to construct a two-dimensional vector current. The geometrical method used to find the vector current will affect the accuracy of the values. The Cartesian method involves locating the range cell in Cartesian coordinates with respect to the centre of the baseline joining the radars. The Cylindrical method uses one of the radar sites as the coordinate system origin; the radial current is found automatically and the tangential component is proportional to the radial term of the other radar. HF radar systems are located at Cape Race and Bonavista and a series of simulations based on their geometry indicate that the Cartesian method is preferrable for the calculation of vector currents.; Due to the limited dimensions of the dual-site coverage, it is desirable to find a way to increase the effective size of the overlap. An approach incorporating the continuity equation uses knowledge of vector currents within the overlap and radial currents outside of it to estimate tangential currents where only single-site data exists. (Abstract shortened by UMI.)...