Report on Technologies and Research Outcomes ... - nowpap dinrac

Technologies and research outcomes related to prevention & collection of marine litterFig 2. Picture of the Tow sled and the mother ship. Images are transmittedvia acoustic modem while the Tow sled is being towed.Acoustic communication systemAcoustic communication system is the main part for the real time surveysystem and is made up of an on deck acoustic modem, while the otheracoustic modem is attached on the survey equipment on the sea bottom,process module, and battery. The underwater image acquisition and processingsystem, which is in the pressure resisting can, receives, processescompresses, and transmits the signal to the deck via the acoustic modems.The images transmitted with this method are sent to the computer which hasa program for displaying and controlling the underwater system. For thissystem, 1,000 meter pressure resisting can which contains commandprocessing and image processing module, a couple of acoustic modems ofabout 1,500 m transmit range, and the battery of appropriate capacity areneeded. The UWM2000 model of LinkQuest was adapted and the maximumtransmission rate of this model is 9600bps. However, the substantial datatransmission rate is 6600bps due to the command processing part with serialcommunication. But the actual speed is expected to vary according to theunderwater transmit environment. Two acoustic modems are located on theTow sled and the mother ship, respectively.11