25-03-2012, 10:21 AM
i m a student of b.tech 3rd yr. i want a full seminar report on topic underwater communication with ppt in pdf
25-03-2012, 10:21 AM
i m a student of b.tech 3rd yr. i want a full seminar report on topic underwater communication with ppt in pdf
26-03-2012, 12:04 PM
to get information about the topic "underwater communication" full report ppt and related topic refer the link bellow
https://seminarproject.net/Thread-underw...ull-report https://seminarproject.net/Thread-under-...munication https://seminarproject.net/Thread-under-...8#pid73728 https://seminarproject.net/Thread-underw...tic-modems
01-02-2013, 02:18 PM
UNDER WATER COMMUNICATION
UNDER WATER.ppt (Size: 1.82 MB / Downloads: 73) Goals of the Project Develop a communication system to transmit video between underwater robot and surface platform Decrease size due to aspase restrictions. Find a good combination of communication speed and robustness. Wireless Communication Technologies Radio Communication 1 High frequency radio Attenuation in water is extremely high Low frequency radio Attenuation is managable Maximum BW is limited Sound Communication 1 For acoustic single transducers the emitter can be considered omnidirectional. In an acoustical communication system, transmission loss is caused by energy spreading and sound absorption Energy spreading loss depends only on the propagation distance. The absorption loss increases with range and frequency. These problems set the limit on the available bandwidth. Visible Range Optical Communication Infrared: The light absorption in water increases towards the red an infrared part of the espectrum Blue Light: Minimal light absorption in water is usually achieved for blue light around 400-450 nm. Fast optical communication Existing models AM Optical Transmission MHz-range frequency response The driving method is noté capable of fully-driving the LED at the highest frequencies FM Optical Transmission FM modulation was chosen over AM modulation since it was viewed as being more resistant to fading and variations in the signal amplitude. This worked fine even though the duty cycle of the pulses was extremely short (4ns at 100kHz).
25-02-2013, 10:57 AM
Underwater Communication
Underwater.ppt (Size: 1.1 MB / Downloads: 40) Introduction Underwater communication is a technique of sending and receiving message below water Typical frequency: 1 Hz to 1 MHz Hydroacoustics Traditional approach for ocean-bottom monitoring Uses sensors to record data Disadvantages: Real time monitoring is not possible. No interaction b/w onshore control systems and the monitoring instruments. failures or misconfigurations may occur Limited storage capacity Challenges Battery Power is limited Limited available bandwidth Channel characteristics UW sensors are prone to failures because of fouling, corrosion, etc Mobility The ocean can be as deep as 10 km |
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