Swath width refers to the strip of the Earth’s surface from which geographic data are collected by a moving vehicle such as a satellite, aircraft or ship in the course of swath mapping. The longitudinal extent of the swath is defined by the motion of the vehicle with respect to the surface, whereas the swath width is measured perpendicularly to the longitudinal extent of the swath. Note that swath width is also cited in the context of sonar specifications. It is measured and represented in metres or kilometres.