American physicists have developed a simple optical technique for tracking blurred or hidden targets. This method uses random light signals to detect moving targets obscured by smoke, clouds, or other scattering media. The researchers claim that this technology can not only be used in the field of military and civilian surveillance, to overcome the limitations of microwave radar and laser pointer, but also in the field of biomedicine.
The remote tracking of moving objects has been widely used in the field of military and civilian surveillance. For example, microwave radars and lidars can transmit electromagnetic waves—where microwave radars use microwave signals and lidars use ultraviolet, visible, or near-infrared light to propagate—and analyze the electromagnetic waves reflected by objects.
Although radar is a powerful tool, there must be no obstacles between the radar antenna and the object. When electromagnetic waves are scattered by clouds, rain, and smoke, the radar’s detection capability will be greatly impaired. Although it is possible to track the obscured object through multiple imaging, this requires complicated equipment and data processing. If these scattering effects caused by various interferences are enhanced, then the tracking effect of this technology will become worse or even fail.
The natural noise interference of the light can show the target location hidden in the smoke. Part of the reason for this problem is that traditional techniques rely on regular wave pulses at a specific frequency or a combination of certain frequency signals to track a shadowed target. A research team member from the University of Central Florida said: “If there is a regular signal, some of which are certain in nature, and passing the signal through some interference, it will be damaged-it depends more or less on the intensity of the interference. ”
Signals that have been destroyed will not be destroyed again. To solve this problem, the University of Central Florida tried another solution. In their latest research published in “Optical Design”, they introduced a technique that uses random green laser pointer optical signals, or “noise” optical signals, to track moving targets obscured by scattering media. This attempt is successful because, although the noise optical signal has been destroyed when passing through the interference, its average nature is still more stable than the regular signal. Signals that have been destroyed will not be easily destroyed again.