I first reviewed the radio propagation software tool, ACE-HF System Simulation and Visualization software for Ham Operators, in the January 2003 issue of CQ Magazine. This well-known analysis and prediction tool has been called "the Cadillac of HF Propagation Programs." That name isn't surprising since the design derives from the professional ACE-HF NETWORK software for government and commercial HF network operators, in use by the military and by commercial groups. This edition of ACE-HF, version 2.05, has many new features for the Radio Amateur, and has even been expanded for use by Shortwave Radio Listeners.

Two words best describe ACE-HF: Visualization and Animation. "ACE" stands for Animated Communications Effectiveness, the copyrighted technique for displaying both transmission and reception area coverage on maps of the world, a feature that I find very informative and helpful. All of the charts used to visualize HF system performance may be animated. These features alone make the product worth investigating for your station.

A few things were noticed immediately. One of them is that ACE-HF PRO Version 2.05 now allows you to show it's screens in either a full-screen mode or in the native 800x600 mode. In past versions, the program always grabbed the entire screen. The fact that you can now have it at a smaller size allows you to run other programs on the same desktop more easily. Have a logging program open, as well as a packet window, along with ACE-HF PRO, and they all work well together. As a matter of fact, creating this review was much easier as I had to capture the screens for this review while writing the review text.



To illustrate ACE-HF's analysis features, I set up a circuit from my station in Brinnon, Washington to Chicago, Illinois, using the intuitive Circuits Inputs Screen as shown above. I didn't expect all-band connectivity, as we are near the bottom of the current solar cycle. For this review, I ran the circuit analysis for April 2006, with a smoothed sunspot number of only 21.





After switching to the Circuit Analysis Screen I used my favorite ACE-HF tool, the SNR (Signal-to-Noise Ratio) Summary Chart, above, which displays predicted SNR for all frequencies and times-of-day. I quickly saw that 20 meters (14.2 MHz) was a good bet for this contact, at least for my time-of-day.



The 20 meter SNR verses time-of-day chart, above, confirmed that at the current time -- shown by blue vertical line -- the band should be open.



This was confirmed by the Best Frequency Chart, above.

To find out who else I could talk to during such a time as this where sunspot activity is so low, I turned my attention to the animated area coverage displays and created predictions for 20-meter coverage from my station. I selected a map centered on the U.S., but I could have displayed worldwide coverage just as easily. When one creates files for all 24-hours, the display first appears for the current hour and advances every hour automatically. I selected the image for 2200 hours UT.



The display, above, confirmed that the Chicago area would be open, but also showed the typical 20-meter fading structure with its many skip zones caused by modal cancellations and reinforcements. The display also revealed the concentration of my transmitter's signal down and to the right on the map. Since I had used a Yagi antenna model, with the main beam set at a 90-degree azimuth, pointing at Chicago, the effect was expected. What wasn't expected was the amazing insight gained when I animated the display through 24 hours! Coverage comes and goes, quickly explaining why certain frequencies are preferred in contest situations. One can also animate the displays as a function of frequency at any time-of-day. This is a great teaching tool for new Ham radio operators.

New ACE-HF features

New in this year's version are many features that will benefit both the Amateur Radio operator and the shortwave listener. You can easily switch the software from Ham Radio mode to SWL mode. In the SWL mode, the transmitter can be set to any location, and you can pick from a database of at least 642 International Broadcast transmit locations. That's just the beginning of the new SWL features, which I've reviewed in the June 2006 issue of Popular Communications in the Propagation Corner column (see my on-line version of the SWL review).

Many other improvements are in the new ACE-HF. You can now select from thirteen service types, including many digital modes. Simulations of both ALE and conventional HF operation can now be made. These are features of interest to Hams now experimenting with Automatic Link Establishment operation.

Antenna Analysis

Perhaps the most interesting new capability is enhanced antenna analysis. In addition to the built-in HFANTENNA program, with which you can analyze and view antenna patterns for the many supplied antenna models or for models that you create, there is a new animated chart for comparing antenna patterns with predicted elevation angles.



One of the most vexing problems in choosing antennas for your station is to figure out the best vertical radiation pattern for a given circuit. This problem is particularly troublesome when short circuits that rely on NVIS (Near Vertical Incidence Skywave) propagation must be accommodated. For NVIS, a simple vertical monopole simply won't do. But at what distance will each circuit work well with your favorite antenna?

The new ACE-HF Antenna Analysis Chart, as shown above, automatically graphs the antenna's vertical acceptance (take-off) pattern along with elevation angles of the arriving propagation modes. The chart may be animated through the user's assigned frequencies and directivity gain is given for each. In the illustration shown above, the chart shows that my selected Yagi antenna's main lobe is at 10 degrees elevation at 14 MHz. Fortunately, the computed elevation angle (the green line) is well within the antenna's emission peak, so this circuit to Chicago should work well. (It sure would be nice to actually have such a Yagi at my place! The wire dipole is nothing compared to the Yagi!)

But what about other circuits? It's easy to just move the receive dot on the circuit analysis screen and see what happens. For NVIS distances, it's clear that another antenna would work better. You can select different antennas without leaving the chart, so comparisons can easily be made. This chart is great fun to play with, and will quickly become a favored tool in you Amateur Radio operation toolbox.

Contesting Aids

With ACE-HF, you can now make simultaneous predictions for up to 18 separate circuits, and the results are displayed on a table like the example for circuits from W1AW, shown below.



You can specify different antennas for each end of each circuit, and can even specify different antenna models for every contest band. The table shows color-coded SNR values for each frequency and can be animated through every time-of-day. You can easily see when different bands are "in the green", and the best frequency is colored blue. The table appears for the current time and then advances automatically every hour. It's a great tool for contesting as you can see at a glance which bands are open, or can advance the time for planning your next contacts.



As another aid to see when the bands are open, you can use the Beacons chart, an example shown above, to show similar predictions from the eighteen NCDXF/IARU Beacon Network stations. In this chart, the predictions update automatically every hour and the white cells advance every ten seconds in synchronism with the beacon transmissions. This allows you to see whether or not a particular beacon could be heard at your location.

Folks often ask which propagation program is the most accurate. Some years ago, the U.S. Navy funded the authors of ACE-HF to determine which HF propagation program was the most suitable for their HF networks. The resulting study selected VOACAP as the most highly validated model and it was then included in the ACE-HF software. VOACAP (widely regarded as the world's gold standard, and the engine used in a small number of well-known propagation tools) is based on the IONCAP operations research model, and was then improved by a rigorous development program funded by the Voice of America. During that development, every potential improvement was subjected to more than 500,000 circuit path-frequency hours comparisons with field data for paths at all latitudes and ranges. Nevertheless, when VOACAP changes that improve accuracy are found, updated files are posted as free downloads on the ACE-HF website.

ORDERING DETAILS

Note: By ordering ACE HF PRO through HFRadio.org, you will support the continuation of the Space Weather and Propagation Center and the eAlert service that I provide. We need your help to keep this website and the resources up and running for everyone's benefit.

ORDER TODAY! To order, please make sure that you mention that you are ordering the program as a result of visiting and/or reading the reviews and information from this website, and from Tomas, NW7US. By doing so, your order will help fund the running of this website. Here's the link: ACE-HF main order weblink at Long Wave Inc. Don't forget to read the Press Release.

BACK TO ACE-HF

© Copyright, 2006, HFRadio.org and ACE-HF PRO. All rights reserved.