These are Hourly Area Predictions (HAP) of communication frequencies based on the previous hours observed conditions for the Global HF ionosphere. As this product depends on global data it can currently only be made for the previous UT hour.

General Charts For Global HF Select one.... Adelaide Athens Atlanta Azores Baghdad Bangkok Barrow Beijing Belgrade Berlin Boulder Boston Brunei Bay Radio Canberra Darwin Darwin-Middle East Dixon Dubai Exmouth-Middle East Exmouth-North Exmouth-South Gander Radio NATA Gander Radio NATB Gander Radio NATC Gander Radio NATD Gander Radio NATF Guam Half Moon Bay Horby Jakarta Johore Kandahar Kansas City Lapaz London Luanda FIR Milan Minneapolis Molokai Montreal New Orleans New York LDOCF New York Radio NATA New York Radio NATE New York Radio CARA New York Radio CARB Orlando Oslo Paris Phoenix Piarco Radio CARA Piarco Radio CARB Reykjavik Rome San Francisco Santa Cruz Bolivia Santa Maria Radio NATA Santa Maria Radio NATE Seattle Seoul Seychelles FIR Shanwick Radio NATA Shanwick Radio NATB Shanwick Radio NATC Shanwick Radio NATD Shanwick Radio NATF Stockholm Tahiti Tokyo Washington DC Whitehorse Winnipeg Vancouver Vladivostok

HAP charts are designed for communications between a specified base and mobile within a nominated area.
• Each chart shows colours which represent the recommended HF frequencies for contacting the ba se or mobile within the area bounded by the chart for a particular hour.

• The geographic zone, which is variable, is represented by a map showing latitude and longitude.

• Charts are in Universal Time (UT).