3D-Cloud Morphology and Motion from Dense Stereo for Fisheye Cameras

Sky imager cameras provide hemispheric images with high spatial and temporal resolution and are commonly used to derive cloud cover and cloud type. A camera pair in a stereo setup in combination with a dense stereo reconstruction technique is used to recover quite complete and consistent cloud morphologies with high geometric complexity over a large part of the hemispheric field of view. A second stereo-camera-pair allows to reconstruct closed cloud boundaries. The technique is efficient and can be automated for an operational use. A validation of a large dataset validated against lidar-ceilometer and cloud radar observations shows good agreement. In combination with Optical Flow methods a cloud motion analysis is conducted and the derived velocities and directions are compared to wind-lidar observations. Products are cloud morphology, cloud height, size, cloud base height and cloud motion, which …