Correlating All Sky Images with Weather Data at the Magdalena Ridge Observatory

The Magdalena Ridge Observatory takes nightly pictures with an all-sky camera for cloud coverage. An automated approach was developed to analyze the images and gather data from them. A multi-program system first located all images in the archive, analyzed average photon counts per pixel, and categorized them into either a “moon” or “no moon” folder depending on the counts. Next, images in each of the folders had different threshold counts to determine the presence of clouds in the image by analyzing standard deviation. In the “moon” files this is accomplished by masking out the moon. Finally, images are examined along with the numeric statistics. Results to date show that the analysis agrees with visual inspection ~70% of the time for images with the moon, and ~88% of the time when the moon is absent. The next steps will be to correlate the cloud coverage statistics with other measurements to determine how many nights per year are viable for astronomical research.