Download Principles of Sonar Performance Modelling by Michael Ainslie PDF

Show description

Towed hydrophones were operational before the end of WW1, and in 1918 a prototype passive-ranging system was fitted to an American destroyer. British listening devices used during WW1, based on early American work, were developed at BIR by Wood and Gerrard (occasionally assisted by Rutherford) at Parkeston Quay and by Captain C. P. Ryan at Hawkcraig. To reduce noise, directional hydrophones could be towed behind the ship in a streamlined capsule known as a ‘‘fish’’, developed by G. H. Nash. Ryan constructed a network of up to 18 underwater listening stations positioned strategically in British coastal waters.

The device was later adapted to enable its use for echo ranging also, leading to an early American active sonar known as the ‘‘QB’’, produced commercially by the Submarine Signal Company. 3 Temperature and the ‘‘afternoon effect’’ Soon after the end of WW1, both British and American scientists working on the recently developed asdics sets noticed that their performance was inconsistent. A 12 The idea itself was not new, but 19th-century attempts had been unsuccessful (Drubba and Rust, 1954; Maury, 1861; Newman and Rozycki, 1998).

Although these produce weaker signals than the seabed, echoes from fish were recorded by the trawler Glen Kidston in the North Sea in 1933 (Cushing, 1973). Even before then, echo sounders were used by Belloc to identify the location of fish shoals in the Bay of Biscay (Belloc, 1929a, b), and by the innovative fisherman Captain R. Balls to find shoals of herring (Hersey and Backus, 1962, p. 499). , with both Wood and Hayes continuing at their respective national research laboratories. In Britain, the Applied Research Laboratory (ARL) was founded in 1921, led first by B.