US Patent 12120434 Sky sensor device

A sky sensor device for measuring direct normal illuminance (DNE) value is described. One method controls a camera sensor to capture a series of exposure-bracketed images having a first dynamic range and generate an image from the series of exposure-bracketed images, the image having a second dynamic range higher than the first dynamic range. The method controls an illuminance sensor to measure a global illuminance value. The method determines a global horizontal diffuse value based on at least the image. The method determines a direct normal illuminance (DNE) value using the global illuminance value and the global horizontal diffuse value.