Tidal phase and amplitude, NW Andros Island, The Bahamas

However, tides in shallow areas are spatially heterogeneous, making it challenging to constrain the geographic structure of tidal phase and amplitude without extensive networks of tide gauges. We present a simple remote sensing method for deriving tidal structure from satellite time series.

Our method is based on two observations: (1) tidally-driven variations in water depth can be detected as changes in pixel intensity in optical satellite imagery, and (2) repeating passes by an orbiting satellite capture a region at different phases of the tidal cycle. By stacking multiple satellite acquisitions of a shallow bank, we can compute the relative tidal phase and amplitude for each pixel location, thereby resolving a detailed map of tidal propagation and attenuation.