An unmanned jet plane flies high over the Afghan landscape, using a technology called synthetic aperture radar, or SAR, to search for signs of Al Qaeda. With its ability to "see" in complete darkness and through rain and clouds in the sky and snow and foliage on the ground, SAR (pronounced "sar" rather than "S-A-R") is becoming a regular component of unmanned aerial vehicles, or UAVs.

Other useful applications for SAR include mapping planets (such as the perpetually cloud-covered Venus), mapping terrain here on Earth, and even looking for signs of earthquakes. For some, what's most fascinating about SAR is not what it can "image" or even that it can produce remarkably high-quality pictures, but that an image can be created at all using radar waves and a moving antenna. To launch the interactive, click on the image at left.


This interactive originally appeared on NOVA's Spies That Fly Web site.