In the previous article of detecting concealed carry weapon
the main focus was to develop your observation/awareness skills of your environment so that you can key in on anything out of place for personal defense.
For public safety using radar technology to detect firearms in public space is not new. The method developed by electrical engineering Professor Kamal Sarabandi of University of Michigan is unique in terms of its practicality. Not only are we talking about detecting weapons but detecting it at distances within a millisecond.
The technology that he developed is currently being used in a number of applications, including collision avoidance systems in cars and in military targeting systems.
The radar itself isn’t particularly unique, but Sarabandi’s pairing of the technology with Doppler radar signal processing allows it to pick out a person in a crowd using a technique called “polarimetry”.
Doppler radar has a range of applications for this application Doppler measures the speed of a given object. Sarabandi used motion capture techniques to identify the reflected signals from the limbs and torso of a human walking, establishing “the DNA of walking.”
A computer is programmed to recognize the pattern, searching for a particular shine on the subjects area, such that a hidden metal object might create. The technology focuses on the pedestrian’s chest as it’s both a common place that people hide weapons and acts as a fairly smooth backdrop, making it easier to pick out anomalies.
The polarimetric radar used by the team works by sending out a signal at a particular polarization, and carefully analyzing the polarization of the signal that bounces back. An irregular metal object can change the polarization of the signal, allowing for the detection of concealed items.
The technology has not been conducted on human testing yet, Sarabandi’s team has carried out a simulation using a mannequin painted with a coat that reflects radar-like human skin. The mannequin was placed on a turntable in an anechoic chamber, a room designed to absorb all echoes and reflections.
The techniques could be used to scan large groups of people, with each subject taking less than a second to process. This would then allow security personnel to closely observe the individual in question or even take suspects aside for more comprehensive scans.
The technology has significant potential to provide extra security in a wide range of applications, and while not entirely infallible, is significantly faster and less than the use of metal detectors.
One point worth noting is that while the technology appears to provide a fairly accurate means of locating hidden metal objects, it might be less effective at spotting some of the 3D printed weapons that are becoming more and more of a security issue as the technology continues to develop. This can be reinforced with more digital examination familiarity training for the operator.
With the 3D printing of firearms becoming more of a hot topic, it’s currently only possible to print certain parts of the weapon, such as the receiver or pistol grip. For a true firearm projectile there will be a hint of metal in the firing pin to make it functional.