SNPP VIIRS Composite Imagery for Cloud Mask Diagnosis and Improved Image Interpretation
These images show SNPP VIIRS data processed through NOAA Enterprise Cloud Mask implemented in CLAVR-x. These data span from January 1, 2016 to the present
The goal of these images is to provide a qualitative assessment of the day-time cloud detection.
These clear and dark composite RGB images may also provide complementary information to the interpretation of traditional RGB images.
Most Current Images
Animations of Images from January 1, 2016 to December 31, 2016
Animations of Images from January 1, 2017 to present
How to Interpret these Images
If the cloud mask is perfect, the clear and dark composites should be similar in appearance. Missed cloud should appear as bright deviations in the clear composite that are missing in the dark composite. In areas with few clear pixels, these deviations can linger through many successive images.
False cloud detection would be seen as areas where the clear-composite has missing data and dark-composite has the appearance of cloud-free data.
Note that regions with dynamic sea-ice and snow cover may also introduce deviations not caused by the cloud mask. Each image link opens a new window so each image type can be compared simultaneously.
- Un-Composited RGB = daily RGB images from ascending SNPP. Pixels with solar zenith angles greater than 80 degrees are classified as missing.
- Dark-Composited RGB = RGB images constructed from the darkest observations at each pixel over the past 28 days.
- Clear-Composited RGB = RGB images updated from clear observations for that day.
Grey pixels are missing. If no clear pixels are available for 28 days, the pixel is classified as missing.
- Clear-Composite Age = number of days since the clear-composite was updated.
- True Color RGB = RGB images made from the 0.47, 0.55 and 0.65 micron VIIRS M-band channels without any Rayleigh correction.
- Snow RGB = RGB images made as described
Snow and ice appear orange and melting snow and ice appears bright orange.