Earth observation satellites are used to measure wave heights. Wave-height data are used to study relationships between sea and air and their meteorological and climatic consequences. Wave height is also very useful information for marine transport and offshore drilling. In fact, each wave is a shape produced by undulations created by the wind in the high seas. Near the coasts, the waveˇs amplitude is determined by the relief features on the ocean floor. The undulation that moves the wave is stopped when it hits the shore.