VOACAP Quick Guide HF Propagation Prediction and Ionospheric Communications Analysis

What is VOACAP?

VOACAP (Voice of America Coverage Analysis Program) is free professional high-frequency (HF) propagation prediction software from NTIA / ITS , originally developed for Voice of America (VOA).

This 'work-in-progress' guide should get you well started with the software. 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 now available on CD-ROM.

There is now also "The Official VOACAP Blog" - well, it's not too official.

NOTE: Running automated scripts to access VOACAP services is strictly prohibited unless agreed upon in advance with the VOACAP site owners.

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Real Propagation Visualized with FT8 Data

Explore the 50,000+ real-life propagation charts from one ITU zone to another ITU zone over the months of 2017-2019!

VOACAP Online Prediction Services

Other VOACAP Related Services

What's New?

1. Downloading VOACAP

2. VOACAP - Backgrounds & Running the Prediction

General

The calculation engine, VOACAPW

Graphs & Colours

3. VOACAP - Understanding the Prediction

General

MUF, SNR and REL

Signal Power & Noise Power

Antennas & Radiation Angles

Conversions

4. VOACAP - Case Studies

5. VOACAP-related Papers

6. NTIA/ITS HF software HELP Topics

7. HamCAP User's Guide

8. Articles of interest

English

Finnish

Swedish

Japanese

9. Tools & downloadable files for use with VOACAP

Downloadables

Software

MAKEVOA.EXE for creating VOACAP-compatible antenna models from HFTA, courtesy of R. Dean Straw N6BV (zipped, 34 kB)

Elevation-Angle Analyzer for VOACAP, v1.0

Windows program (zipped, 830 kB) for conversion of on-line CTY.DAT to CTY.GEO [9 Dec 07]. Mac and Linux versions available upon request!

Perl source code for conversion of WL_CTY.DAT to CTY.GEO

Coordinate files

Antenna and configuration files

I wish to thank Mr George Lane for his friendship, invaluable comments and guidance - and his patience in this project. A special thank-you to Greg Hand who still maintains the code.

Disclaimer: Any software or service on this website is provided "as is". Use at your own risk.

© 2003-2020 Jari Perkiömäki OH6BG/OG6G. SSN source for all VOACAP Online services: WDC-SILSO, Royal Observatory of Belgium, Brussels. Last update: 2 January 2020.