NAVIGATION is a quarterly journal published by the Institute of Navigation (ION). The journal publishes original, peer-reviewed articles on all areas related to the science and technology of air, sea, land and space navigation, including estimation of position, velocity, attitude, and time, and the technologies that support the determination of these quantities. The Institute of Navigation is the world’s premier non-profit professional society dedicated to the advancement of the art and science of positioning, navigation and timing (PNT). Founded in 1945, it serves a diverse community including those interested in air, space, marine, land navigation, and position determination. Its membership is worldwide, and it is affiliated with the International Association of Institutes of Navigation.