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LW1EAA > TODOS 26.10.17 15:02l 228 Lines 11066 Bytes #999 (0) @ WW
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VOACAP Quick Guide
HF Propagation Prediction and Ionospheric Communications Analysis
by Jari Perkiömäki, OH6BG/OG6G
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 prohibited unless agreed upon in advance with the VOACAP site owners.
DO-IT-YOURSELF VOACAP PREDICTIONS FOR WEBSITES
I am happy to announce that VOACAP Online has now an option to offer do-it-yourself HF propagation predictions, suitable for the websites of DXpeditions (and for other needs, too). Just embed a simple snippet of code in your HTML codebase, and you are set to go. It's free. Read more at: http://www.voacap.com/diy-charts.html
IMPORTANT NOTICE ABOUT SUNSPOT NUMBERS!
A key VOACAP input parameter is the Sun Spot Number (SSN). The National Geophysical Data Center (NGDC) / National Oceanic and Atmospheric Administration (NOAA) has, at the end of 2016, discontinued providing this invaluable predicted data, instead directing users to the SIDC website.
Jim Watson, one of the key figures behind VOACAP Online and a maintainer of his own Proppy website, has conducted a survey, comparing the effects of three SSN data sets: Original NOAA values, SIDC values, and adjusted SIDC values. The results indicate that VOACAP performs best with the original NOAA SSN values. Now, going forward, we will need to use 'adjusted' SIDC SSN values as a substitute.
Read Jim's blog post or the full version (as PDF).
VOACAP Online Prediction Services
Point-to-Point Predictions
11M Point-to-Point Predictions
Coverage Area Maps
11M Coverage Area Maps
VOACAP Propagation Planner
Visual tool for HF contesters and DXers VOACAP DX charts
Predictions for upcoming DXpeditions
Other VOACAP Related Services
HF Propagation Monitoring Skimmer VOACAP Greyline
What's New?
Current International Smoothed Sunspot Numbers, Ri, to be used in VOACAP, from NOAA/NGDC (updated until 2020)
Current Space Weather: Solar Wind, Magnetogram, X-Rays, Protons
QTH Locator - find coordinates and Maidenhead locators on Google Maps
How to Run VOACAP under Apple Macintosh OS X? - a quick guide to making text-based VOACAP predictions
Elevation-Angle Analyzer - generate statistical elevation-angle data for HFTA
Statistical elevation-angle distribution - a case study
Graphical User Interface for VOACAP for Linux
Rockwell Collins offers VOACAP User's Guide on CD-ROM for free (shipping charges apply)
World Radio Broadcasting Stations - explore various BC transmitting sites on Google Maps
My blog in Finnish: VOACAP, ennusteet ja antennit
Sunrise and sunset times around the world
Today's Sunrise and Sunset Times by DXCC country
1. Downloading VOACAP
Download from Greg Hand's site, all new updates of the ITSHFBC package are available here
Alternative direct download, 8 Dec 2009 version (3.1 MB)
Download from the home of VOACAP, NTIA/ITS, this ITSHFBC page has not been updated for long
The 8 Dec 2009 version
The 26 Mar 2009 version
Download the Fortran source codes of the VOACAP Propagation Prediction Engine, in a special directory as ZIP files.
VOACAP for Linux by J.A.Watson (M0DNS), an exciting project to make VOACAP available for Linux users. Please contribute!
Release 3 is out! Download the new VOACAP Linux GUI, Release 3! (1.5 MB gzipped file). Now supports Area Coverage Maps with Jim Watson's VoaAreaPlot! This software is supplied 'as is' without any warranty, implied or otherwise. right-click and save the target. All users of Release 1 are strongly encouraged to upgrade, due to the bugs in R1.
VOACAP for Linux Software
The voacapl application: voacapl-0.5.7.tar.gz
The itshfbc directory: itshfbcFiles18Apr08.tar.gz
The python scripts to display the output
2. VOACAP - Backgrounds & Running the Prediction
General
VOACAP Overview
Screenshots of VOACAP
Modelling the real-life HF communication system into VOACAP
Setting VOACAP input parameters
Textual circuit prediction (Run > Circuit)
Graphical circuit prediction (Run > Graph)
Area coverage prediction (VOAAREA)
The calculation engine, VOACAPW
An introduction to VOACAPW.EXE
The FREQUENCY card in VOACAPX.DAT
Graphs & Colours
VOACAP & VOAAREA contours
VOACAP & VOAAREA plot colors
Y-axis scaling for VOACAP Time & Distance graphs
3. VOACAP - Understanding the Prediction
General
Ten Common Mistakes in Using VOACAP
Field Strength vs. Signal-to-Noise
Choosing the correct Sunspot Number
VOACAP Predictions at Low Frequencies
Comparing VOACAP, ICEPAC and REC533
Method 25: Ionospheric Parameters and Semi-thickness
MUF, SNR and REL
The MUF and SNR Distribution: Choosing the Best Frequency
Understanding Above-the-MUF Predictions
Calculating the MUFdays
Maintaining the Required Grade of Service: Calculating the Circuit Reliability for a Given Hour
Signal Power & Noise Power
Summing Signal Power from Multiple Modes
Calculating the Received RF Noise Power
Antennas & Radiation Angles
Method 15, or Transmitter & Receiver AntennaPatterns
VOACAP Angle Predictions
Minimum Angle in VOACAP
Predicting the Takeoff Angle Parameter TANGLE
Conversions
S DBW to S Meter Correlation Table
The Z Tables
4. VOACAP - Case Studies
VOACAP Case: Make your beacon predictions
VOAAREA Case: RUV Gufunes
5. VOACAP-related Papers
Using Propagation Predictions for HF DXing [2010] Visalia 2010 presentation by Dean Straw, N6BV.
Contest Antennas. DX or Domestic, What’s Your Pleasure? [2009] Visalia 2009 presentation by Dean Straw, N6BV.
What’s the Deal About “NVISö?, [2005] article courtesy by Dean Straw, N6BV
Another Way to View Propagation Predictions for DXing and Contesting [2006] Visalia 2006 presentation by Dean Straw, N6BV.
In Search of the Ultima Thule. Can VOACAP Help Find the Ultimate QTH? [2006] CCF/OHDXF presentation by Jari Perkiömäki & George Lane.
Improved Guidelines for Automatic Link Establishment Operations [2005] by George Lane
Graphs for the paper [2005]
Review of the High Frequency Ionospheric Communications Enhanced Profile Analysis & Circuit (ICEPAC) Prediction Program [2005] by George Lane
Required Signal-to-Interference Ratios for Shortwave Broadcasting, [7.2 MB] by George Lane, 1997
Predicting Signal-to-Interference Probability in the High Frequency Band, [60 kB] by George Lane and Greg Hand, 1997
Strategies Using Propagation Predictions for DXing and Contesting, by Dean Straw, N6BV
What is VOACAP Trying to Tell Me? by Dean Straw, N6BV
How Does VOACAP Compare With These Measurements, by Dean Straw, N6BV
6. NTIA/ITS HF software HELP Topics
General information on the NTIA/ITS HF Propagation Analysis Package
VOACAP. General information - Point-to-Point - Area Coverage - Signal-to-Interference.
Voice of America Coverage Analysis Program
VOACAP Frequently Asked Questions (22-Feb-96 Version)
ICEPAC. General information - Point-to-Point - Area Coverage - Signal-to-Interference.
Ionospheric Communications Enhanced Profile Analysis and Circuit Prediction Program
REC533. General information - Point-to-Point - Area Coverage.
ITU-RS Recommendation 533. This has been updated to the ITU 1996 Version 3.
Data Files Frequently Asked Questions
Helpful documents on using the propagation models
History (Part 1) of HF propagation models by Ray Rosich, 1978
Introduction to the ICEPAC Technical Description
Excerpts from Original ICEPAC User's Manual
Corrections to Man-made Noise
Note on MUFDAYs
High Latitude Errors
Corrected Signal-to-Noise Ratio Distribution
A Comparison of Broadcast Quality to VOACAP using Methods 21, 22, and 30
VOACAP Method 30. A Long Path/Short Path Smoothing Function
7. HamCAP User's Guide
HamCAP v1.5 User's Guide
HamCAP and Type 13 & 14 Antennas
8. Articles of interest
English
The Woody Woodpecker Story, Part 3 [PDF, 115 kB] by V. K. Lehtoranta, OH2LX
Jamming, or deliberate interference against radio broadcasting stations [PDF, 140 kB] by V. K. Lehtoranta, OH2LX
www.radiojamming.info by Rimantas Pleikys
Finnish
Kokeiluja Faroksella - automaattinen kelimajakoiden kuuluvuudenmittaus vs. keliennusteet
Tee-se-itse täsmäennuste YLE Radio Finlandin lähetyksille
VOACAP ennustaa kuuluvuuden signaali-kohinasuhteen avulla
VOACAP taajuussuunnittelun työkaluna
Avaruussään vaikutuksesta HF-keliin
Avaruussään tarkkailua IonoProbella
Swedish
VOACAP förutspår hörbarheten med hjälp av signal-noiseförhållandet
Japanese
HamCAP 1.5 User's Guide [PDF, 49 kB]
9. Tools & downloadable files for use with VOACAP
Find coordinates and Maidenhead grid locators just by pointing and clicking
Browse the World with Google Maps, (start view: World)
Browse the World with Google Maps, (start view: Scandinavia)
World Radio Broadcasting Stations on Google Maps! new
QTH Locator (Google Maps), updated!
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
Save the coordinate files (*.GEO) at C:\ITSHFBC\GEOCITY\
New country coordinate list from CTY.DAT by AD1C. [9 Dec 07]
GEO file for all Zones (WAZ). Courtesy of Peter Ackermann DL3NAA.
Latest Global HF Transmitter Site List. [5 Aug 06]
Latest country coordinate list by OH6BG. [30 Jul 06]
Latest NCDXF beacon coordinate list [30 Jul 06]
Finland city coordinate list
Antenna and configuration files
A collection of antennas for use with VOACAP is available. If you wish to contribute, please let me know.
Fine-tuned VOACAP Point-to-Point parameter auto scaling settings, English. Save as C:\ITSHFBC\DATABASE\Voacap.gph
Fine-tuned VOACAP Point-to-Point parameter auto scaling settings, Finnish. Tallenna nimellä C:\ITSHFBC\DATABASE\Voacap.gph
Fine-tuned Y-axis scaling for VOACAP Time & Distance graphs. Save as C:\ITSHFBC\DATABASE\voadist.gph
Fine-tuned colors for auto-contour shading for Point-to-Point plots. Save as C:\ITSHFBC\DATABASE\Colors.gph
4NEC2, a free NEC-based antenna modeler and optimizer by Arie Voors, can export antenna models to VOACAP antenna format
Special Thanks
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.
© 2003-2017 Jari Perkiömäki OH6BG/OG6G. Last update: 23 July 2017.
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