This file contains features derived from sky images obtained for Folsom, CA (lat=38.642N, lon=121.148W). The file is in comma-separated values format. The file has 16 columns. The first column is the timestamp in UTC in the format yyyy-mm-dd HH:MM:SS. This is the time when the image was captured. The other 15 columns list values for OPERATOR(ImageData), where OPERATOR can be: AVG: the average of the sky image pixels STD: the standard deviation ENT: the entropy The ImageData can be: R: the red color channel G: the green color channel B: the blue color channel RB: the Red-to-Blue ratio R/B NRB: the normalized Red-to-Blue ratio (R-B)/(R+B)