FCC Lets Radar Company See Through Walls
Novel technology approved after almost two year
Regulars here know about the problems faced by innovators whose ideas do not conform to the FCC’s technical rules.
A recent case in point is L-3 CyTerra, a division of L-3 Communications Corporation. Its new radar device, intended for police, fire, and homeland security personnel, can look through walls to detect people on the other side – even immobile hostages or unconscious fire victims.
Most civilian radars use the same principles worked out during World War II. They emit a short pulse of radio waves at some frequency and analyze the echo to deduce the direction, the distance, and possibly the speed of the target. The FCC routinely approves this kind of product.
But that approach would not do the job for L-3 CyTerra. It is easy enough to send a radar pulse through a wall and into a room on the other side. Coming back, though, would be dozens of echoes bouncing off multiple walls, furniture, and people, with no way to sort them out.
Instead, the L-3 CyTerra device sends pulses on 200 different frequencies, one at a time, ranging in sequence from 3101 to 3499 MHz at 2 MHz intervals. The whole cycle repeats 54 times per second. Each of the pulses still reflects from multiple surfaces. But the circuitry combines the echoes at different frequencies in such a way that the echoes from stationary objects fade into the background while those from moving objects stand out. The system is sensitive enough to detect the chest motions of a person who is unconscious but breathing, or the slight swaying of a person trying to stand perfectly still.
A radar that uses 200 different frequencies is not consistent with the FCC’s technical rules. No rule expressly forbids such a device, but neither is there a rule under which the FCC can authorize it. L-3 CyTerra accordingly requested a waiver, which the FCC granted. Read the waiver order here.
The waiver grant is the good news. The bad news is the 21 months the FCC needed to process the request, despite of a total lack of opposition. (That in itself is unusual; here in Washington, somebody opposes almost everything.) It may be that the FCC staff took time at the front end to consider whether some other procedure, less time-consuming than a waiver, might have accomplished the same purpose. Another possible source of delay is the same one we see every four or eight years: a new Administration installs a new FCC Chairman, who in turn re-staffs the top FCC posts with new people, who then need time to familiarize themselves with a very long list of pending matters.
But let us not dwell on the negatives. We can applaud the fact that, thanks to technology and the FCC’s approval, our first responders have a new tool to help them help us, particularly in emergency situations. Next, maybe somebody will develop a type of radar capable of detecting and rescuing immobile administrative proceedings from the file drawers of our federal agencies . . .
Posted on December 2, 2009 by Mitchell Lazarus
apologies if this story is a bit off topic. My first thought when I read that it could detect the subtle movement of a person trying to be perfectly still was that it could most certainly pick up marijuana plants gently moving under fans.