A Contrast Minimization Approach to Remove Sun Glint in Landsat 8 Imagery

Sun glint, i.e., direct solar radiation reflected from a water surface, negatively affects the accuracy of ocean color retrieval schemes if entering field-of-view observing instrument. Herein, simple and robust method to quantify sun glint contribution top-of-atmosphere reflectances in visible near-infrared is proposed, exploiting concomitant observations glint’s morphology shortwave infrared. The method, termed Glint Removal through Contrast Minimization (GRCM), requires high spatial resolution (ca. 10–50 m) imagery resolve characteristic morphology, meeting additional criteria on radiometric resolution, signal-to-noise ratio, temporal delay between individual band’s acquisitions. It has been applied with good success selection cloud-free Landsat 8 Operational Land Imager (OLI) scenes, otherwise encompassing wide range environmental conditions terms observation geometry, intensity, types, as well aerosol Rayleigh optical depths. GRCM entirely image based does not require ancillary information sea surface roughness or related parameters (e.g., wind), nor presence homogeneous clear areas under consideration. GRCM’s limitations are discussed, its potential for sensors other than OLI applications beyond removal sketched.