John M. Ozard
Esquimalt Defence Res. Detachment, FMO Victoria, BC V0S 1B0, Canada
John P. Todoeschuck
407-6 Argyle Ave., St. Lambert, PQ J4P 2H5, Canada
The prediction of transmission loss is a long-standing problem in Arctic sound propagation. Some earlier estimates failed to predict the observed losses by a factor of 2. These estimates used levels of ice roughness that were believed to be characteristic of the Arctic. A 1400-km long profile of upward looking sonar from near northern Greenland to the vicinity of the pole was examined. The statistics of the ice roughness are not stationary over this profile. The ice is rougher near the shore. Thus the transmission loss would vary over the profile depending on the roughness. A range of transmission losses that bracket observed values was found.