March 10, 2011: Five years after the first portable, wall penetrating, radar, went to Iraq, there have been several generations of more reliable and capable devices developed and shipped. The latest one is Prism, whose improvements largely have to do with speed (the image of what is behind the wall is produced faster) and accuracy (more detail is shown) and reliability (more resistance to dust, water and rough treatment.) The Prism battle weighs 5.6 kg (12.3 pounds), has an eight hour battery and a range to 20 meters (63 feet). Throughout this period, the devices have retained their small size (hand-held) and weight (under 6 kg/13 pounds).

Three years ago, two years after the first of these systems, RadarVision, became available, the Xaver 400 arrived. This one weighed 3 kg (6.5 pounds), and could see through non-metal walls at a range of up to 20 meters (63 feet). The battery lasted 2.5 hours and the device could broadcast images, up to a hundred meters, to another display.

The original RadarVision showed up in Iraq in 2006. This was particularly welcome, as urban warfare is particularly difficult because, once inside a building, you have to deal with all those walls. Well, just like advances in electronics resulted in a solution to night fighting (night vision goggles), a similar device was developed for literally seeing through walls. Well, at least most walls. The nine pound RadarVision couldn't see through metal walls, but would give you an image of anyone behind any other wall material, including up to a 30 cm (12 inches) of brick, concrete or stone. It could also see through multiple walls. Using a 90 minute battery pack, the image was particularly good if someone in there was moving. RadarVision was also incorporated in some combat robots. Such a droid could check out a building more quickly by using its RadarVision to see through walls while moving down a hallway. Many Iraqis long believed that American troops had devices that could see through walls. Then they discovered that this particular fantasy was actually true.

Two years ago, RadarVision 2 showed up, which has similar capabilities as Xaver 400. Both of these devices sell for between $20,000-$30,000, but the Prisim is even cheaper. Police departments buy a lot of these, as well as military organizations that can afford to provide their infantry with high-priced gear.