Islands, sand banks and coral reefs play a crucial role in marine economic development. But negligence in the past led to improper exploitations, and thus incurs a waste of resources and destruction of environment. Remote sensing, capable of large-scale, real-time, simultaneous and high-frequency dynamic monitoring at a lower cost, has become increasingly important in environment survey. It can not only help researchers quickly learn about the surroundings and utilization of the islands, sand ba...