Clouds play a significant role in the earth's radiation
balance and the hydrological cycle. Their shape, size,
composition and movement indicate the weather and climate
changes. Nowadays, clouds are studied by means of satellites
or ground-based remote sensing. Satellites can provide global
cloud information, but information of the lower cloud under the
upper cloud is often lost. In addition, the global cloud
information, which is at a low spatial resolution, cannot meet
the need of meteorological research and weather forecasting.
On the contrary, ground-based cloud observation can provide
detail information of local region, which can be used to support
cloud studies.