A Review on Deep Learning-Based Approaches for Automatic Sonar Target Recognition

Underwater acoustics has been implemented mostly in the field of sound navigation and ranging (SONAR) procedures for submarine communication, the examination of maritime assets and environment surveying, target and object recognition, and measurement and study of acoustic sources in the underwater atmosphere. With the rapid development in science and technology, the advancement in sonar systems has increased, resulting in a decrement in underwater casualties. The sonar signal processing and automatic target recognition using sonar signals or imagery is itself a challenging process. Meanwhile, highly advanced data-driven machine-learning and deep learning-based methods are being implemented for acquiring several types of information from underwater sound data. This paper reviews the recent sonar automatic target recognition, tracking, or detection works using deep learning algorithms. A thorough study of the available works is done, and the operating procedure, results, and other necessary details regarding the data acquisition process, the dataset used, and the information regarding hyper-parameters is presented in this article. This paper will be of great assistance for upcoming scholars to start their work on sonar automatic target recognition.

Acoustic Signal Attenuation Determination Technique Traveling Through Obstacles

This paper presents a novel technique for calculation of attenuation of acoustic signals in the materials in underwater channel. A laboratory procedure and algorithms have been developed for finding attenuation. In many applications like sonar signal processing acoustic signal attenuation in the dome or in an enclosure are required to be known. Finding the actual attenuation while signal passes through the materials is very useful in calculating the precise power transmitted through the enclosures. The attenuation in materials mainly dependent on type of material, signal frequency and launch angle of the signal. A proper procedure has been presented in this paper