Infrared cloud imaging for diurnal remote sensing of cloud statistics including cloud type

Clouds are a critical component in determining weather and climate. Spatial and temporal statistics of cloudiness are needed in applications ranging from climate research to precision agriculture. Ground-based cloud remote sensing is particularly useful in applications requiring high spatial and temporal resolution. Thermal infrared imaging allows continuous detection of clouds from their thermal emission, with no interruption during sunrise, sunset, or night. In addition to detecting clouds continually during day and night,the third-generation Infrared Cloud Imager (ICI-3) is capable of classifying thin clouds according to their optical depth. This added capability is provided by a rigorous radiometric calibration and compensation of atmospheric emission from the infrared sky images. Data are shown that illustrate the importance of cloud- type classification in determining the radiative effect of variable cloudiness.