Abstract:

This dataset includes selected points and their sun glint strength values of image pairs which were used in determining the sun glint threshold required for remotely sensing oil films in the northern Gulf of Mexico. The satellite imagery used in the analyses were collected by Moderate Resolution Imaging Spectroradiometer (MODIS) Terra (MODIST), MODIS Aqua (MODISA), and Visible Infrared Imaging Radiometer Suite (VIIRS) instruments. The dataset includes original raw file lists of the imagery used and information about how they can accessed can be found in the Supplemental Information section of the metadata. Post processing MODIS Rayleigh corrected reflectance (Rrc) data, VIIRS radiance data and corresponding RGB true color images are provided. The datasetset corresponds to the following publication: Sun, S., and C. Hu (2016), Sun glint requirement for the remote detection of surface oil films, Geophys. Res. Lett., 43, 309–316, doi:10.1002/2015GL066884.

Suggested Citation:

Sun, Shaojie. 2017. Dataset for: Sun glint requirement for the remote detection of surface oil films. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7BZ641J

Publications:

Sun, S., & Hu, C. (2016). Sun glint requirement for the remote detection of surface oil films. Geophysical Research Letters, 43(1), 309–316. doi:10.1002/2015gl066884

Purpose:

This dataset was used to quantify sun glint requirement of oil film detection for MODIS Aqua, MODIS Terra and VIIRS in Gulf of Mexico.

Data Parameters and Units:

MODIS L0 and VIIRS L1B data were used as raw data. MODIS L0 data can be downloaded from 'http://oceancolor.gsfc.nasa.gov/', VIIRS L1B Imagery data can be download from 'http://www.nsof.class.noaa.gov/saa/products/search?datatype_family=VIIRS'. Since the raw data can be assessed online and they are in large size, only the file list of these raw data are provided the directory ‘..\data\raw_file_list\’. MODIS data were then processed to Rayleigh corrected reflectance (Rrc) data and can be found in the directory ‘..\data\modis_rrc_and_rgb’, which includes MODIS Rrc hdf data and RGB true color image. VIIRS radiance data and RGB true color images are found in directory '..\data\viirs_radiance_and_rgb\'. The corresponding LGN value of image pairs (oil exists, and detected)/(oil exists, but not detected) as well as (oil exists, and detected)/(oil exists, and detected) were documented in file '..\data\record_glint.xlsx'. The following is a description of each variable in the record_glint.xlsx file: record – unique identifier (ID); time – date of processing (YYYYMMMDDHHMMSS); pixel – selected pixel position in identified line of image swath (number); line – line number of selected pixel (number); lat – selected image pixel latitude (dd); lon – selected image pixel longitude (dd); day – date of images (yyyyddd); gmt_diff – difference in time between image 1 and image 2 (image 1 – image 2, hhmmss); sensor1 – sensor type for image 1 (A = MODIS Aqua, T = MODIS Terra, V = VIIRS) oil1 – oil detected in image 1 (1 = yes, 0 = no); glint_coef1 – normalized glint reflectance (LGN) for selected point in image 1 (sr^−1); std_glint1 – standard deviation of LGN for selected point in image 1 (sr^−1); sensor2 – sensor type for image 2 (A = MODIS Aqua, T = MODIS Terra, V = VIIRS) oil2 – oil detected in image 1 (1 = yes, 0 = no); glint_coef2 – normalized glint reflectance for selected point in image 2 (LGN, sr^−1); std_glint2 – standard deviation of LGN for selected point in image 2 (sr^−1); image1 – file name of image 1 (text); image2 – file name of image 1 (text); In folder named ‘figure4’, the spreadsheet has the look-up-tables (LUT) for LGN. 'relaz0wind3' means the LGN LUT when relative azimuth angle is 0 and wind speed is 3m/s. Each tab in the spreadsheet has the same naming convention. The x axis is solar zenith angle while y axis is sensor zenith angle. When LGN > 0.05, LGN was represented by 0.05, and when LGN < E(-8), LGN was represented by E(-8).

Individual Files: