This file gives information about new advanced technology in underwater navigation. The development of medium and long range Ul V s, associated with most recent operational concepts create new requirements for advanced underwater navigation systems that must be accurate, easy to deploy at sea and low cost -This file gives information about new advanced technology in underwater navigation. The　development　of　medium　and　long　range　Ul V s, associated with　most　recent　operational　concepts create new　requirements　for　advanced　underwater　navigation systems that must　be accurate, easy to　deploy at sea and low cost