Sound ranger
Sound rangers are military specialists who locate enemy artillery using sound. They use equipment such as super-sensitive microphones to pick up the sounds of firing. By using a combination of surveying techniques and trigonometry they then calculate the locations of enemy batteries. These results are then transmitted by radio to their own artillery, who used it for targeting.
Sound rangers were used extensively in the Second World War. Many of the officers were former surveyors, estate agents and geographers because of their surveying experience in civilian life. They would be located near the front line but not always among the firing line for their safety.
