Artillery sound ranging
Sound ranging was one of three methods of locating hostile artillery that rapidly developed in World War I.
Sound ranging has a number of advantages over other methods: Sound ranging also has a number of disadvantages: Military forces have found various ways to mitigate these problems, but nonetheless they do create additional work and reduce the accuracy of the method and the speed of its deployment.
It brought together the necessary sensors, measurement technology, and analysis capabilities required to do effective sound ranging.
Like many technology concepts, the idea of using sound to locate enemy artillery pieces came to a number of people at about the same time.
World War I provided the ideal environment for the development of sound ranging because: While the British were not the first to attempt the sound ranging of artillery, it was the British during World War I who actually fielded the first effective operational system.
[10] In mid-1915 the British assigned the scientist and Nobel Laureate Sir William Lawrence Bragg to the problem.
This problem was solved in mid-1916 when one of Bragg's detachment, Lance Corporal William Sansome Tucker, formerly of the Physics Department, London University, invented the low-frequency microphone.
This separated the low frequency sound made by the firing of the gun from the sonic boom of the shell.
Other matters were researched including the optimum layout and positioning of a 'sound ranging base' – the array of microphones.
It appears that in Britain this led to better microphones and recording apparatus using heat sensitive paper instead of photographic film.
Another innovation in the late 1930s was development of the comparator, a mechanical computer that calculated first order differential equations.
During World War II, sound ranging was a mature technology and widely used, particularly by the British (in corps level artillery survey regiments) and Germans (in Beobachtungsabteilungen).
At the end of the war the British also introduced multiplexing, which enabled microphones to share a common field cable to the recording apparatus.
[15] During the Okinawa campaign, the US Army used its sound ranging sets to provide effective counter battery fire.
Since anti-radar countermeasures were limited at this time and the UN had air superiority throughout the war, these approaches were simpler and more accurate.
Australia deployed a sound ranging detachment from 1967 to 1970 in Vietnam, which operated a cross-base to provide all-round observation.
[21] Also, during this period the British deployed ad hoc "Cracker" batteries, with sound ranging and mortar locating radars, to Borneo and Oman.
In the early 1970s an effective VHF radio link was introduced that enabled the APs to switch-on the recording apparatus.
Each unmanned cluster listened continuously for sound, calculated the bearing to the source and recorded other characteristics.
The production system, ASP (Advanced Sound Ranging Project), entered British service in about 2001.
The UK designed systems are now manufactured by Leonardo S.p.A., (and also formerly under the BAE and Selex names)[22] At the turn of the century it was being adopted by several other armies, including the United States Marines.
[23] The same principle underpins the RAZK artillery sound ranging complex,[24] developed independently in Ukraine from the Russian AZK-7M/1B33M system.
As mentioned in the short description at the beginning of this page, Acoustic Multi Mission Sensors found their inroads.
Muzzle blast noise may attenuate down to a level no longer detectable at the sensor post, but even if it does, the speed of the sound being slow and modern artillery moving on after firing (shoot & scoot), obtaining a localization might be simply too late.
Another trend is the increased prevalence of rockets that, having a self-propelled phase, hardly generate muzzle blast noise.
As compared to the muzzle blast noise, the 3D shockwave signal has a higher initial sound level, attenuates only in two directions, and usually comes from the sky when arriving at the sensor post.
The concept of operation should be based upon deploying the sensor posts on in-fleet vehicles being present in battlespace.
On one hand, this makes the concept very affordable, as there are no operational costs for a dedicated task like a sound ranging regiment used to have.
