Opto- Electronic System for Real Time Monitoring of Motions in Stratified Fluids
The present invention elucidates an innovative method and system for real time monitoring of motions in stratified fluids (like waves and mean currents in the ocean and atmosphere). The novel system is applied to monitor internal waves and tsunami waves simulated in a laboratory tank filled with stratified salt water. An inter comparison of the data recorded using this invention and the data records obtained from an ocean industry standard pressure transducer, variations of which are currently being used for surface wave and tsunami wave monitoring by many researchers around the world, demonstrated the efficacy of this invention as a sensitive method for real time monitoring of ocean waves.
The opto-electronic system described herein is an in situ device which could be deployed in the ocean for the real time monitoring of ocean waves like surface waves, internal waves, tsunamis etc. Ocean is a stratified fluid medium. The opto- electronic system for real time monitoring of ocean waves comprises of a (any) continuous wave, coherent, collimated beam of light (or a laser) falling on the surface of a (any) photo detector in such a way that the received light falls on the active sensing areas of the photo detector, after passing through the stratified fluid medium. That is the stratified fluid medium spatially separates the light source and the photo detector. The light intensity falling on the photo detector undergoes changes due to changes in the optical refractive gradient generated as a result of wave motions in the stratified fluid (caused by surface waves, internal waves or tsunami waves). The photo detector records the precise time varying light intensity pattern, corresponding to the time varying motions experienced in the stratified fluid due to wave motions. The output signals from the photo detector are recorded and compared with those obtained from a standard pressure sensor. The efficacy of this method and system for real time monitoring of ocean waves is demonstrated.