Title
An alternative approach to determine critical angle of contrast reversal and surface roughness of oil slicks under sunglint.
Abstract
The critical angle is the angle at which the contrast of oil slicks reverse their contrasts against the surrounding oil-free seawater under sunglint. Accurate determination of the critical angle can help estimate surface roughness and refractive index of the oil slicks. Although it's difficult to determine a certain critical angle, the potential critical angle range help to improve the estimation accuracy. In this study, the angle between the viewing direction and the direction of mirror reflection is used as an indicator for quantifying the critical angle and could be calculated from the solar/viewing geometry from observations of the Moderate Resolution Imaging Spectroradiometer (MODIS). The natural seep oil slicks in the Gulf of Mexico were first delineated using a customized segmentation approach to remove noise and apply a morphological filter. On the basis of the histograms of the brightness values of the delineated oil slicks, the potential range of the critical angle was determined, and then an optimal critical angle between oil slicks and seawater was then determined from statistical and regression analyses in this range. This critical angle corresponds to the best fitting between the modeled and observed surface roughness of seep oil slicks and seawater.
Year
DOI
Venue
2018
10.1080/17538947.2018.1470687
INTERNATIONAL JOURNAL OF DIGITAL EARTH
Keywords
Field
DocType
Sunglint,critical angle,natural seep oil slicks,surface roughness,MODIS
Racing slick,Histogram,Moderate-resolution imaging spectroradiometer,Total internal reflection,Remote sensing,Sunglint,Geography,Brightness,Surface roughness,Refractive index
Journal
Volume
Issue
ISSN
11.0
9.0
1753-8947
Citations 
PageRank 
References 
0
0.34
5
Authors
8
Name
Order
Citations
PageRank
Yansha Wen100.34
Mengqiu Wang210.72
Yingcheng Lu373.09
Shaojie Sun400.34
Minwei Zhang594.18
Zhihua Mao6149.52
Jing Shi713.40
Yongxue Liu8408.38