HFTA online: HF terrain analysis in your browser

HFTA-X shows how the real terrain around your tower changes the elevation pattern of your HF antennas, one direction at a time. Its engine is compatible with HFTA, the classic HF Terrain Assessment by N6BV. Nothing to install, it works on any computer, and you don't have to build terrain profiles by hand.

Open HFTA-X

What it does

Automatic terrain profiles. Click your tower on the map and type the azimuths, for example 0-355/45. HFTA-X builds the profiles from SRTM elevation data (about 30 m resolution). No MicroDEM, no USGS downloads.
The HFTA engine. The calculation is a line-by-line port of the core that reproduces HFTA 1.04: geometric-optics ray tracing, Fresnel reflection over lossy ground and UTD diffraction. The figure of merit (FOM) uses the ARRL .PRN elevation-angle statistics.
Yagis and stacks. A dipole or a Yagi of 2 to 8 elements, stacked up to four high, with out-of-phase feeding. Compare heights and sites before you put up the tower.
Height optimizer. It sweeps a range of heights and tells you which heights work best, by FOM or by average gain over a window of angles. It also optimizes pairs for 2-high stacks.
Propagation with VOACAP. It crosses the terrain result with VOACAP coverage to show which angles you need towards each area of the world.
Your files still work. It reads and writes classic HFTA .PRO profiles, exports OUT.PRN for MAKEVOA/VOACAP, and gives PDF and CSV reports.
Built for daily use. Projects are saved in your browser and can be exported. Metres or feet, 12 languages, light and dark themes.

Does it give the same results as HFTA?

Yes, within a few tenths of a dB. The official HFTA manual prints eight figure-of-merit values calculated by N6BV, with real terrains, heights, frequencies and statistics. HFTA-X recalculates them from the same .PRO and .PRN files and ranks the options the same way in all eight cases. The differences are around a few tenths of a dB, well below anything that would change a decision about tower height.

Questions

Is there an online version of HFTA?: HFTA itself is a Windows program distributed by the ARRL. HFTA-X does the same job in the browser, with an engine compatible with HFTA, and also works on Mac, Linux and tablets.
Can I use my existing .PRO files?: Yes. Import them to calculate with them, or export the profiles HFTA-X builds and open them in the original HFTA.
Where does the terrain come from?: From the SRTM digital elevation model, downloaded automatically for the area you choose.
Who makes it?: Armando Clemente, EA5RA, a contest station builder in Spain. HFTA-X is part of the tools at ea5ra.com.

HFTA-X is an independent project. It is not affiliated with or endorsed by the ARRL. HFTA (HF Terrain Assessment) is a program by R. Dean Straw, N6BV, published by the ARRL.