The Distant Early Warning System (DEWLine) is a network of radar and communications stations stretching for some 3600 miles along the 69th parallel from Cape Lisburne, Alaska, to Cape Dyer, Baffin Island, and continuing across Davis Strait and the Greenland ice sheet to the east coast of Greenland. Thence it maintains communication with the North Atlantic Radio System from Keflavfk, Iceland, to Fylingdales Moor, England. The DEWDrop system, a tropospheric scatter communications system links Cape Dyer with the Inter-Continental Ballistic Missile Station at Thule, Greenland and another connects Thule with the DEWLine station FOX, on Foxe Basin. DEWLine stations are supervised and controlled by the US Air Force, by agreement with the Canadian and Danish Governments.