Clouds - cloud cover retrieved from infrared measurements at 10 minute intervals at CESAR observatory

Four cloud cover parameters are retrieved continuously from sky temperature measurements by a scanning infrared radiometer (NubiScope). These parameters are resp. total, low -, middle - and high level cloud cover. Only measurements 20 degrees above horizon are used to create a hemispherical cloud mask. The temperature deviation of a sky pixel from an estimated background sky temperature determines whether a pixel is considered to be cloudy or clear sky. For more information about CESAR: https://ruisdael-observatory.nl/cesar/