Marine Doppler Radar Surface Current Measurements in the Surf Zone

This paper presents a comparison of microwave radar surface velocity estimates to the estimates derived from video observations in the surf zone. The data presented here were collected during the Nearshore Canyon Experiment (NCEX) in the fall of 2003. The radar estimates are inferred from the Doppler shift of the backscattered radiation while video velocity estimates were produced using particle image velocimetry (PIV) technique. Comparisons of longshore velocity estimates show high spatial correlation within the central surf zone. The comparisons of the near cross-shore velocity shows the importance of bore velocity removal while showing high spatial correlation when the bias is removed. Both alongshore and cross-shore velocity estimates display discrepancies in the breaker and the swash zones.