The Use of Normal Mode Analysis to Extend HF Radar Coverage Over Enclosed Bays

A technique referred to as Normal Mode Analysis (NMA) has recently been developed for representing total vector CODAR HF radar data. This technique has been applied to Corpus Christi Bay. These modes satisfy the coastal boundary constraint of no flow normal to the shore, and inherently represent both divergent and rotational flow as two sets of ortho-normal basis functions. The use of NMA allows the measurement of flows in mostly enclosed bays, like Corpus Christi, where wind-driven and tidal currents predominate. Furthermore, it extends the measurement coverage into regions where only one, or even no radar is able to provide coverage. The PDE2D software, which is based on a Finite Element Method, is used to obtain the eigenfunctions for the Corpus Christi Bay. Comparisons are made with the real-time total-vector maps produced by the HF Radar data over the common coverage area.