A statistical method was developed to enable them to distinguish the light waves reflected from the moving target and scattered by the scattering medium at the frequency of the light wave. However, this method is only applicable when the target and the scattering medium are moving at different speeds, which means that they will return a different spectral combination. When you get the laser pointer light intensity change, you can get the spectrum of these fluctuating light sources, and then you can find different frequency bands in this spectrum. This operation can be performed in real time, because no complicated calculations are required-this is just a light source spectrum analysis.
The researchers tested this research idea. They placed a small object in a Plexiglas box with a scattering coating composed of synthetic acrylic resin on the surface. Then they used a primary light source to illuminate a beam of coherent light on the wall of a scattering box, creating a secondary light source inside the box. The light beam scatters onto the object and generates more randomness, then returns through the acrylic box wall, then passes through a tube equipped with a photomultiplier tube, and the photodetector detects the light signal. Through statistical analysis of the signals, the researchers were able to trace the complete three-dimensional trajectory of the object. This is an effective way to measure signals obtained from any location outside the scattering box.
Further details This technique cannot provide detailed information of the tracked object, but can only obtain the direction and velocity of the object’s movement, and the general shape of the object based on the strength of the green laser pointer based on the object’s reflected signal. Just as you want to know more about objects, you need more expensive and complicated tests, he added: “This is just a simple way to detect whether (objects) move and the direction of movement.”
The researchers are currently planning to test in a realistic outdoor environment, adding that although they have verified this detection technique in the optical band, this method should also be applicable to sound signals and microwave signals. They are also exploring the possibility of applying this technology to biomedicine.