'4-D' ionosphere map helps flyers, soldiers, ham radio operators

“The best way to appreciate the 4D ionosphere is to try it,” says W. Kent Tobiska, president of Space Environment Technologies and chief scientist of its Space Weather Division. Instructions may be found at http://terra1.spacenvironment.net/~ionops/ES4Dintro.html

Within minutes of downloading the files, Google Earth will appear on your computer screen, the globe wrapped in an atmosphere of vivid color. “Colors represent electron content,” Tobiska explains. “Bright red is high density; that’s where radio communications are restricted to few or no frequencies. Blue is low density; no problem there.”

Using the intuitive Google Earth interface, users can fly above, around and through these regions getting a true 3D view of the situation. Make that 4D. “The fourth dimension is time. This is a real-time system updated every 10 minutes.”

The 4D model can be fun and even a little addictive, warns Tobiska, who likes to use it to pilot an imaginary plane over the Arctic. “A growing number of commercial business flights are crossing the Arctic Circle,” he says. “It’s the shortest distance between, say, Chicago and Beijing and many other major cities.”

The ionosphere is particularly important to these lucrative flights. While they are over the Arctic, planes lose contact with most geosynchronous satellites and must rely on “old-fashioned” radio communications—a link that could be severed during a radio blackout. Using the 4D model, a flight controller could examine the ionosphere from the flyer’s point of view and use that information to anticipate problems that could cause a flight to be delayed or diverted.

The proper name of the system is CAPS, short for Communication Alert and Prediction System. Earth-orbiting satellites feed the system up-to-the-minute information on solar activity; the measurements are then converted to electron densities by physics-based computer codes. It is important to note, says Tobiska, that CAPS reveals the ionosphere not only as it is now, but also as it is going to be the near future. “Forecasting is a key aspect of CAPS available to our customers from, e.g., the Department of Defense and the airline industry.”

Contributing partners to the development of CAPS include the Space Environment Corporation of Utah, Air Force Research Laboratory of Massachusetts, and IPS MeteoStar of Colorado.

Start your own flight at http://terra1.spacenvironment.net/~ionops/ES4Dintro.html.