A method and apparatus for providing a repeat calling service feature in a communication network are disclosed. Distance sensors continuously acquired distance measurements to the surface of the substrate which is to be imprinted. The system comprises an inflatable pneumatic float and a mast which serves to house the meteorological and oceanographic instrumentation, as well as a group of elements for communication, electromechanical components, and an anchorage system. It could be constructed with low resolution liquid crystal screens to realize large size real-time color 3-D display, which could widely be applied to 3-D computer or TV screens, 3-D human-machine interaction, machine vision, and so on.