High-Frequency Underwater Acoustic Propagation in a Port Modeled as a Three-Dimensional Duct Closed at One End Using the Method of Images

Abstract

A computer-efficient model for underwater acoustic propagation in a shallow, three-dimensional rectangular duct closed at one end has been developed using the method of images. The duct simulates a turning basin located in a port, surrounded with concrete walls, and filled with sea water. The channel bottom is composed of silt. The modeled impulse response is compared with the impulse response measured between 15 kHz and 33 kHz. Despite small sensor-position inaccuracies and an approximated duct geometry, the impulse response can be modeled with a relative echo magnitude error of 1.62 dB at worst and a relative echo location error varying between 0% and 4% when averaged across multiple measurements and sensor locations. This is a sufficient level of accuracy for the simulation of an acoustic communication system operating in the same frequency band and in shallow waters, as time fluctuations in echo magnitude commonly reach 10 dB in this type of environment.

Underwater MANETs: A Specialized Protocol (RANR) for Routing the Packet

“…The connection store additionally transfer it to the tracking network. The FAU-DPAM [14] utilized in the proposednetwork introduces every message with anaccepted recognition succession that is utilized to recognize atransmissions received. Unlike whatever is left of the information which consists coded client information, the discovery succession is totally known, so it is significantly less demanding to recognize.…”

“…In contrast to DSR, RANR incorporates a connection topology forecast system and quality measures. Dynamic Source Routing protocol utilizes shortest path routingprotocol that has been appeared to implement inadequately in very portable systems [14]; RANR's utilization of the Conventional Transmission Count (CTC) interface quality metric enables it to settle on moreeducated choices, giving better path through the network. Explicit data that which travels inprotocol header of aninformation is utilized to traverse the route and the topology information.…”

“…System execution was creating to endure more when the model of medium overevaluated correspondence quality under poor natural circumstances. This channel display has been particularly intended to precisely speak to the DPAM's FSK [14] execution over an extensive variety of ecological parameters.…”