A comparative analysis of Landsat TM and radarsat SAR signatures in restricted tidal channels

In this study we examine and comparatively analyze synthetic aperture radar and near infrared Thematic Mapper signatures observed in the restricted tidal channel of a shallow lagoonal estuary. Both imaging systems show coherent structures, identified as longitudinal convergence zones, that appear as bright and dark bands aligned parallel with the axis of the tidal channel in question. This result indicates that Doppler shifting is not the mechanism responsible for the observed SAR signatures. Furthermore, modulation of relative intensity shows similar trends in location and magnitude of peak intensity with respect to tidal phase. Background variances from the unperturbed regions also show similarities between the two sensor systems. Finally, TM imagery, in the context employed here, is limited by the solar illumination cycle with the optimal period from May through August for the northern latitude site examined here.