A key give-away of a submarine is its periscope which rises out of the water’s surface in order to keep an eye on the enemy. Researchers are now working on a ‘virtual periscope’ which would let a submarine view above surface from under the water.
The new system has been developed at Technion-Israel Institute of Technology and it is called Stella Maris. Stella Maris is the short form for Stellar Marine Refractive Imaging Sensor. Until now, it wasn’t possible for a submarine to peek above water’s surface without a physical periscope.
But Stella Maris is a brilliant new solution to this riddle. The problem with light, any light, reflected through water is that it is bent. Exactly to what extent is this light bent, is a complex calculation. Moreover, since any view of the world above water passes through the surface to reach a submarine or a viewer under water, it is distorted due to this bending of the light.
Stella Maris gathers light from sun on a grid of holes in a metal sheet, located under water. Under this grid is a glass image plane. Since the Sun’s location is constant at a given time, the key calculation here is to determine the movement of the waves. To do this, researchers see the movement and shape of the light reflected through the grid on to the glass. The pattern of light points gathered in this way is then compared against what a normal light pattern would be.
This gives the researchers that key difference between reality and the distortion at any given time. Now any picture taken under water at this time can be improved by applying this difference to its results. This is a major break-through and although work is still being done on the Stella Moris system in the lab, we can expect this technology to find an application not only in submarines but a number of other fields.