Integrated Navigation System for Remotely Operable Vehicle for 6000m Water Depth

Many underwater positioning techniques have been developed as response to the increase in exploration and exploitation of ocean resources. Though there are many techniques available most successful ones are based on acoustics. Electromagnetic radiation suffers heavy losses in water and can not travel long distance in oceans. Even with the modern navigation equipment like GPS etc. it is not possible to determine the position and track the underwater objects and submersibles without employing subsurface navigational aids. Though techniques such as dead reckoning and inertial navigation are often employed for this propose the cumulative errors are large and for better results periodic correction of the position is required. As the sound is the only radiation that can travel long ranges in oceans underwater Acoustic Positioning Systems have been employed to fix the position of underwater objects and sites and the advent of modern computers Underwater Acoustic Positioning Systems reliable and versatile. However at longer depths acoustic positioning systems alone can not provide the high accuracy and fast update rates. Hence combinations of acoustic and other navigational systems have been recently developed. National Institute of Ocean Technology (NIOT) and Experimental Design Bureau of Oceanological Engineering (EDBOE), Russia have developed an ROV for 6000m (ROSUB 6000) water depths. To meet the challenge of positioning and tracking of the ROV at 6000m depths an Integrated Navigation System combining inertial navigation system and acoustic positioning system with other aids like Doppler velocity log has been developed.