Voice of America Coverage Analysis Program VOACAP
VOACAP is free professional high-frequency (3-30 MHz) propagation prediction software from NTIA/ITS, originally developed for Voice of America (VOA). This online guide should get you well started with the software.
Need a user manual?
A more comprehensive discussion about the finer details of using the software can be found in George Lane's book Signal-to-Noise Predictions Using VOACAP. A User's Guide. The book is available on CD-ROM from Rockwell-Collins.
Running any scripts to access VOACAP services is strictly prohibited unless agreed upon in advance with the VOACAP site owners.
VOACAP for Ham Radio
HF propagation predictions from 3.5 to 28 MHz.
VOACAP for Marine HF
HF propagation predictions from 2 to 25 MHz.
VOACAP for 11M
HF propagation predictions from 26 to 28 MHz.
VOACAP DX Charts
HF propagation predictions for amateur radio DXpeditions.
Sun-related data for any given location, e.g. times for sunrise, sunset, dawn, dusk, solar midnight.
Real-time Kyoto DST, Tromso A Index, Ap and Kp indices, and proton flux.