Problem:

1. Communication needs to exist between base station and robots
2. Robots need to be located

1. A system to communicate with AUV’s
2. A system to determine the location of AUV’s inside blue hole
3. A system to determine location of AUV’s outside blue hole
4. A system to communicate with ROV’s

1. Place 4 relays which emit and receive frequencies of about 1khz in blue hole.
   • 3 relays will be placed along the same level in blue hole
   • A fourth relay will be placed at a lower level.
2. A system similar to ( i ) can detect the exact position of the AUV in the blue hole by knowing the time difference of the received signal.
3. The 3 relays will locate the AUV along the x-y plane, but in order to find its location along the z- axis, a pressure sensor should be placed on the AUV
4. We will attach an optical fiber to communicate with an ROV. The system is made up of:
   • A transmitter that changes electric energy into light pulses and directs it into the optical fiber.
   • A regenerator which repeats the signal (because signal loss occurs when pulse is transmitted through fiber)
   • An optical receiver that we will place on the ROV. It uses a photocell that converts digital light signals into electric (sound) energy.