ASI

The all sky imager (ASI) is a ground-based 5-megapixel camera that uses a fisheye lens to provide a 180-degree field of view of the sky during daylight hours. Infrared-cutting filters and an anti-reflective quartz dome (housing the camera and lens) help minimize the effects of sun flare. High dynamic range imaging further helps manage the contrast between the sun and the rest of the image.

JPG images are provided at 30-second resolutions from local sunrise to sunset, and these images are compiled to create a daily movie. Cloud fraction and cloud opacity (thin, immediate, thick) classification are retrieved from all images that are collected at solar elevations greater than 5 degrees.

• Cloud fraction
• Cloud location