HAP charts are designed for communications between a specified base and mobile within a nominated area. In cases where the base operator and base antenna are not co-located, the location of the base antenna should be specified as the base location. For example, if the base operator is located in Tokyo, Japan while the base antenna is located in Noheji, Japan, then Noheji should be specified as the base in the HAP chart.
HAP chart features:
- Each chart shows colours which represent the recommended HF frequencies for contacting the base or mobile within the area bounded by the chart for a particular hour. The base operator and the mobile should use the SAME frequency denoted by the colour at the location of the mobile.
- The geographic zone, which is variable, is represented by a map showing latitude and longitude.
- Charts are in Universal Time (UT).