Stereo Camera Cloudiness Map Product Moves to Production

 
Published: 9 October 2023

Clouds Optically Gridded by Stereo (COGS) data from ARM’s Southern Great Plains atmospheric observatory are presented for May 4, 2018. The top plot shows the number of cloudy grids as a function of time and height above the ground. Cloud base heights estimated as the 1% of the cloudy grid heights are marked with black dots. The bottom plot presents vertically projected cloud fraction. Both plots cover 18:04 UTC through the rest of the day. Maximum cloud fraction is shown over 0.8 (before 21:32 UTC), and the minimum is 0.0 after 18:04 and 23:15 UTC.
Clouds Optically Gridded by Stereo (COGS) data from ARM’s Southern Great Plains atmospheric observatory are presented for May 4, 2018. The top plot shows the number of cloudy grids as a function of time and height above the ground. Cloud base heights estimated as the 1% of the cloudy grid heights are marked with black dots. The bottom plot presents vertically projected cloud fraction. Cloud fraction at a time is calculated as the fraction of the number of vertically projected cloudy grids over the total number of available grids at the level of estimated cloud base height at the time.

The Clouds Optically Gridded by Stereo value-added product (COGS VAP) is now in production for the Atmospheric Radiation Measurement (ARM) user facility’s Southern Great Plains (SGP) atmospheric observatory.

COGS provides a four-dimensional (4D) map of cloudiness, which is generated from multiview stereo reconstruction using a ring of stereo cameras at the SGP. The VAP also includes a vertically projected cloud fraction and cloud base height estimate. These data are useful for studying the life cycles and macrophysical attributes of shallow cumulus clouds.

COGS is produced by stitching together three-dimensional (3D) reconstructed cloud points from the SGP’s three pairs of stereo cameras. It covers a 6-by-6-by-6-kilometer region of the SGP Central Facility centered at the position of the Doppler lidar. The grid resolution is 50 meters in horizontal and vertical directions and 20 seconds in time.

Production data are available from September 1, 2017, through October 27, 2019. Access the data in the ARM Data Center. (To download the data, create an ARM account.)

The images and cloud point data used to generate COGS are also available in the ARM Data Center as the Point Cloud of Cloud Points (PCCP) VAP.

More information about COGS is available on the VAP web page. To ask questions or provide feedback, please contact Rusen Öktem or David M. Romps.

To cite the COGS data, please use doi:10.5439/1877293.

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ARM is a DOE Office of Science user facility operated by nine DOE national laboratories.