Space-based Cloud Bottom Lidar

A high altitude lidar system propagates a beam of laser pulses through clearings in a cloud formation which reflects off the surface of the earth thereby providing first earth surface returns and reflections towards the base of a cloud that again reflects the pulses back towards the earth surface to be reflected again to provide cloud base returns. The time differential between the earth surface returns and the cloud base returns are used to determine the altitude of the base of the cloud.