On modeling of the air transmission channel for sonar systems

Time and frequency domain models of the air transmission channels for sonar systems, narrow and wide frequency range are considered. The objective of the investigation if the estimate de waveform at the point where scattering might occur and at the point of the reception, if the scattering and reflection phenomena are known. Approximate transfer functions were established for various discrete distances from the usual range of the sonar were considered. Local and general models are presented and discussed. Simulation results are discussed in two cases narrow and wide frequency ranges. The studies is pointing the effects of air channel over ultrasonic waves and prepare the framework to investigate models and effects of the targets described by the change in the received signals.