Degree of conformity with a standard. Accuracy relates to the quality of a result and is distinghished from precision which relates to the quality of the operation by which the result is obtained.
Members of the US Geological Survey were filmed while out on the Missouri River at Williston, North Dakota, USA, performing a hydrographic survey to monitor the state of riverbed erosion. They were using a multibeam echo sounder which transmits sound energy and analyses the return signal (echo) that has bounced off the riverbed or other objects. Multibeam sonars emit sound waves from directly beneath a ship's hull to produce fan-shaped coverage of the riverbed.
