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Software review

The "Solar data" window and the cursor showing a K-index of 9 on July 27, 2004.

DX ToolBox propagation analysis and prediction program (II)

Solar and Geomagnetic Data

The “Solar and Geomagnetic Data” window displays 5 bar-graphs with the next readings:

- Daily Solar Flux (named Fs or I or other products)

- A-Index

- Smoothed Sunspot Number (SSN)

- Background X-Ray Flux

- K-Index forecasted for the next 3 hours.

The value of each plot can be highlighted by passing the mouse over the bar.

These data are a graphical representation of the GOES 10 and 12 satellite readings. They are as important as the X-ray flux. Higher is the solar flux and the number of sunspots, higher will be the MUF (maximum usable frequency).

A low A and K-indices associated to a low X-Ray flux will improve the propagation. However, a high individual value can break an ionospheric layer too (K=9 for example is the sign of auroral activity).

These data have thus to be interpreted with care with a good knowledge of the dynamic of the solar and geomagnetic activities, which obey to very complex mechanisms where interact strength fields with plasmas.

In all five charts, bars change gradually from green to red color according to the index value. But at mid-scale the color is green-reddish, a bad color that seems "fuzzy" or screen, not pleasant. I suggested to the publisher to allow the user to change the color and maybe the type of chart because the green-apple color looks a bit too fluo on screen.

At last as we told previously, if you work offline, if you try to open this window the program displays an exception fatal error and shuts down. The same problem occurs randomly working online in trying to open this window before any other one excepted the Current conditions. This fatal error should be handled by the system or corrected in a next released of DXTB.


The “Images” window allows you to display near-real-time images or graphs downloaded from various servers such as SEC/NOAA without user intervention but one mouse-click.

Among the images downloaded, name the auroral oval, several maximum F layer frequency charts (related to MUF) calculated over various parts of the world, the last images of the Sun recorded by SOHO, etc.

Click first on the “Options” button to lists all images that you want to select/deselect and loaded. Click then on the “Reload” button to reload all of selected images in a few minutes.

In addition, you can also specify other source of images to download. Press on the “Extra Images...” button, then on “Add” button, and you will get another combo message box allowing you to enter a description and the URL of a website. These additional links are saved in a separate text file "ExtraImages.txt" that you can edit.

The “Images” window. Here is the well-known auroral oval extrapolated from NOAA-15 by NOAA. At that moment a strong activity is developing over south Scandinavia and South Canada/ North America correlated with other charts. The “Extra Images…” button allows you to add external links. Their list is saved in a separate text file.

Add for example those images (Description and URL):

Pixie Dynamic Bow shock and magnetopause (static)

Sunspot number progression (SWPC)

10.7 cm radio flux progression (SWPC)

NGDC ionosonde

6 hours forecast of geomagnetic activity (Canada)

The two next images cannot be loaded as the file name changes from one frame to another :

Belgium digisonde

Predicted sunspot number and radio flux (table)

If you are searching for other reports, bulletins or pictures to add to this list, I suggest you to check the SWPC Products and data Library.

Now, to update the list you must close and re-open the “Images” window for the changes to take effect. The new images will appear at the end of the list.

Do not enter an URL to an image which name changes every day or you will get an error… Select only those using a generic name.

NB. On July 28, 2004, the publisher fixed a problem that happened when loading images on XP/ME. Only the first or first two loaded. The fix is installed in DX ToolBox version 2.2.0 exe file which is also slightly smaller that the previous one.


The “Reports” window is very interesting to take knowledge of the latest bulletins, warning messages and other text reports released by observatories monitoring propagation conditions or the space weather.

In the current “Reports” window you can only read one report at a time. I suggested to the publisher that it would be interesting to create a multi-instance object of this window in order to access simultaneously or so to several reports displayed in several windows in order to compare easier several documents side by side. 

These reports come from the SEC FTP website. Not all are “clear” and understandable for the novice or even an advanced amateur. Most require to be familiar with the solar and geomagnetic activity and some require even to know some codes to translate figures in text… Excepted this, several reports are however accessible to everybody.

The following reports are available :

- WWV Geophysical Alert

- 27 Day Space Outlook

- 45 Day AP Forecast

- Geomagnetic Data

- Daily Geomagnetic Data

- Daily Particle Data

- Daily Solar Data


- Daily Magnetometer Analysis Reports

- Hourly Magnetometer Analysis Reports

- Predicted Sunspot Numbers and Radio Flux

- Report of Solar-Geophysical Activity

- Solar and Geophysical Activity Summary

- Solar Region Summary

- Weekly Highlights and Forecasts

- Current Space Weather Indices

- Space Weather Event Reports

- Daily Space Weather Indices

- Summary of Space Weather Observations

- 3-day Space Weather Predictions

The Grayline Map

As its title suggests, this window displays a gray line map of the world in cartesian projection. The gray line is not correlated with the sun activity but we know that this line separating the day from the night (also called the terminator) is the location where low and medium altitude ionized layers vanish on the night side permitting sky waves to reach the F-layer, and thus to reflect further with less hops, and the opposite on the daylight side. Using the gray line is an excellent method to reach far DX.

First error, the program doesn't check the date format. The default format is MM/DD/YYYY. If you enter DD/MM/YYYY the program accepts the entry and calculates something even if the month is greater than 12 but it doesn't update the map.

Thanks to the Propagation Path calculator, clicking anywhere on to the Grayline map you can get the propagation conditions at the target location, its longitude and latitude (roughly, without decimal), distance in kilometers, as well as the antenna bearing.

On request you can display the short path to the target location but there is no possibility to display the long path and get a propagation chart for this antipodal direction, although it is often very useful to take advantage of the darkness to reach far DX.

At the limits of the map or close to the pole the program shows also some erratic paths because high angular values are not correctly taken into account (see p3).

DXTB provides also a beacon monitoring incrusted on the Grayline map. You can get the location and call sign of the currently transmitting NCDXF/IARU beacons in selecting the right frequency (14100 kHz, 18110 kHz, etc) in the scrolling dialog box displayed in the below right corner of that window.

At left, the “Grayline Map” window with IARU beacons monitoring activated on 14100 kHz. At foreground the "Propagation map" predicts a 7 dB signal (S5) to 5Z; in the field in was S1 only. At right, a forecast calculated for 100 W PEP from K to TZ on 40 meters in fall time.

For the publisher, in inserting this feature the idea is to allow you to (try to) listen simultaneously to the various beacons in tuning your radio on their frequency. The next page devoted to SWL activities recalls how work these beacons.

Most of them use vertical antennas (isotropic radiation) at medium or low power (100 W to 0.1 W) and help many amateurs to “feel” the radio propagation conditions and openings toward such or such country (or to be accurate from the DX to your location). Added to the other tools provided with DXTB (Propagation path and MUF/LUF estimations), you will better understand why such or such beacon arrives loud and clear to you or is unreadable.

Sometimes however, the signal strength estimation displayed in the "Propagation map" does not match the real conditions experimented in listening beacons or working DX stations, that they are close or far away from your home. We are here outside the capabilities of the program because it is a prediction tool working with median and monthly values, suited to estimate future conditions not to "forecast" the current status of the ionosphere in spite of its real-time updates. At so short-term propagation conditions fluctuate at a scale by far smaller than what permits the current ionospheric sounding network.

That said, to get a better estimation of the signal strength and chances to work such or such DX, the program should also take into account a complete communication circuit and not only the locations, date, time, SSN and the output power. We will come back in detail on this subject in the last page.

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Propagation Map

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