Radar as an Aid to Air Navigation in the Arctic

Abstract

Hgs. 1,2. The top photograph, taken from an aircraft at i 2,000 feet, shows the contrast between land and water areas during the summer when no ice is present. The lower photograph, taken in August over an ice-bound inlet, illustrates the bright radar returns from ice, the low-lyinq terrain remaining relatively dark. MNINSUIA (Rmiyh Tern,,,,) FJORD LASD . 3 , 4 . In fig. 3, taken over an ice-filled channel, the brilliant returns from the ice obscure the outline of the rough terrain, lig. 4 shows how pack ice can resemble a land mass on the scope. SMOOTH ICE ISLAND ISLAND Figs, c,, 6. The returnsfrom two types of ice along a low cliff coast are shown in the top photograph. The rough ice and terrain present similar pictures, whereas the smooth ice shows dark. Fig. 6 is a scope photograph of an island taken in mid-winter. The land area is dark compared to the surrounding ice. ROUGH TERRAIN PATCH OF OPEN WATER ROUGH TERRAIN ,'-. T \V \ S V OUTCROPPlNGS'-% Figs. 7, 8. The rough terrain and rugged coastline stand out well against the ice-bound channels in the top photograph. The outcroppings shown in Fig. 8 provide a good radar target, and remain a prominent feature throughout the year. The land and pack-ice returns will be seen to be of about the same intensity, making it difficult to pick out the coastline.

Navigation on some recent R.A.F. Flights in High Latitudes

“…(most probable position) technique, which in turn placed a premium' on accurate dead reckoning supplemented by visual or radar drift and windfinding. 2 Some thought was given to the possibility of using the air position indicator in conjunction with gyro-steering, but those ideas were finally discarded on the grounds that the resulting complications would outweigh the advantages of a mechanical airplot. However, although the airplot had to be maintained manually some assistance was obtained from the air mileage indicator, which provided an automatic record of air distance flown.…”