High Latitude HF Communications

The well-known difficulties of HF in polar regions have spurred studies on means of improving arctic communications. The studies have proceeded in two directions: 1) optimum circuit design, irrespective of frequency and 2) means of improving HF circuits. For long-haul circuits, the former study indicated that serious consideration should be given to submarine cable between Europe and North America via the Arctic Ocean. The latter study concludes that a grid of closed-loop, oblique-incidence, sweepfrequency sounders together with rapid switching techniques has potential.