Modern underwater means of protection against terrorist acts are now smart devices. The best option for these devices is that they can be controlled remotely. The present work concerns underwater remote control of explosive devices. Specific applications of the remote device developed by the team are also.
The influence of seawater depth in hydroacoustic transmission of binary numbers is experimentally investigated. The binary digits are encoded as sequences of short and long rectangular pulses of a fixed duration. The experiments are carried out in coastal waters of Bulgarian South Black Sea shelf. The transmission of numbers is experimentally compared for three different water depths: 10m, 30m and 60m, at a transmitter-receiver distance of 1500m. Increasing the water depth improved the performance leading to a larger number of correct transmissions. Hydroacoustic transmission in very shallow water is more difficult due to strong interference from reflected signals. In 60m deep water the observed transfer of binary numbers is stable and correct. Certainty of correct transmission increases with increasing water depth in shallow seawater.
Hydroacoustic waves are used to experimentally transmit binary numbers underwater. The numbers are first encoded into pulse sequences, according to the encoding scheme: two consecutive short pulses for a digit zero and two consecutive long pulses for a digit one. A clock period determines the timing of the encoding pulses. The influence of the clock period duration on the number of correctly transmitted binary numbers is tested in 30m deep coastal seawater, at a 1500m distance. The performance is compared at three different periods of the clock: 10ms, 20ms and 40ms. Increasing the clock period of the encoding pulses leads to an increase in the number of correct transmissions. At the longest tested clock period of 40ms all the transmissions of binary numbers are successful. Certainty of correct transmission increases at the longer clock periods of the encoding pulses due to attenuated interference from reflected signals.