Evolution of Sonar Survey Systems for Sea Floor Studies.

Abstract

Approximately 71% of our planet is covered with oceans. It is also known that oceans are the last frontiers for the mankind's survival and therefore it becomes pertinent that they are studied in great details. It has been found that the exploration of the oceans can be done more precisely using acoustics as one of the methods, as the acoustic waves can propagate over large distances and also using a broad spectrum of frequencies various issues of the ocean studies can be addressed more effectively than many of the other methods, both in terms resolution (using high frequency components) of measuring parameters and over large ranges (using low to very low frequency components). Currently with the technological advancement and improved computing algorithms, we have state of art systems for ocean exploration, which can provide information about the sea floor, sub-surface including ocean floor classification. These could be projected in 2-D and 3-D visualization to a great accuracy. Also available are acoustical methods wherein one can obtain an extremely important information about water column properties (both in terms of bioinformation and physical properties), and has great importance as this water column is the medium for transmission of all kind of energies(acoustic for short, medium and long ranges and some time light source for exploration over a very short distance) that are used for exploration on the oceans. It will therefore be interesting to understand the progress of underwater acoustics from its very primitive stage, where acoustic transmission through water medium was used for first time to the present day highly complex but very advanced acoustic sea-floor surveying systems. It will also be interesting to know, with a very old maritime history of using seas for transportation, as to what were the methods used by early time seafarers to understand depths of the oceans they were sailing. It has taken almost a century in developing an acoustic system to arrive at the present day advancement. An attempt has been made to present a perspective of evolution and advancement in underwater acoustics and related electronic, material and computational advancement, starting from the early attempts to the modern day acoustic equipments

Cause Analysis and Preventive Measures against False Bottoms in Echosounder Data

“…In 1906, Lewis Nixon invented the first sonar receiving device for the purpose of detecting icebergs [1]. With the outbreak of World War I, sonar technology garnered significant interest from researchers.…”

Xây dựng mô hình số 3D địa hình đáy biển dựa trên phương pháp đường cong tham số

“…Mỗi hệ thống MBE bao gồm nhiều hệ thống đo lường như đầu sonar, hệ thống định vị, cảm biến chuyển động hoạt động đồng bộ. Bên cạnh đó, công nghệ đo sâu SONAR cũng đã được phát triển để có thể lập mô hình 3D địa hình đáy biển một cách trực quan với độ chính xác cao [13]. Diện tích biển và đại dương của thế giới rất rộng lớn, nếu thu thập dữ liệu địa hình đáy biển theo các phương pháp truyền thống sẽ cần rất nhiều thời gian để thực hiện.…”