figs

This path, with terminals at 43.5 deg. S and 77.5 deg. S (geographic) crosses the auroral zone. Its mid-point is generally on the high latitude ionospheric trough so that only occasionally will single-hop propagation apply. The predictions in this note are based, therefore, on two-hop propagation. The low-altitude reflection point in the two-hop path is close to Campbell Island, so this station is used as a control point. The high latitude reflection point lies within the polar cap and Antarctic predictions (see Tech. Note no. 55) can be adapted for it, using Scott Base as reference station. The recommended operating frequency is, of course, the lower of the frequencies which will work through the two control points. (auth)