As you know, a Wi-Fi signal can pass through any (well, almost any) obstacle, and German scientists were able to use this property to learn to "see" through walls.
The idea is based on the analysis and registration of the forms created by electromagnetic waves, which are reflected from objects when moving around them. That is, in simple terms, scientists have learned to recognize objects that "stream" the Wi-Fi signal waves even through walls.
How it works?
The study related to the method of 3D visualization of these signals began as a student thesis project, before moving on to a larger work - this follows from a publication in Physical Review of Letters. The technique described in the study is capable of rendering at a rate of 10 times per second and recreating the internal structure of an entire building in large-scale simulations.
“If you have a cup of coffee on the table, you can see that there is a small object on the table, but you cannot recognize its distinct shape,” Philippe Hall, a physics student at the Technical University of Munich who co-authored the study, told Business Insider. "But you can easily recognize a person or, for example, a dog, but in fact, any object larger than four centimeters."
Hardware and algorithm
Promotional video:
The method involves the use of a Wi-Fi transmitter as a low-power radar with two antennas: one of them forms a 2D plane, and the other captures the signal relative to the data of the first.
Once the antennas collect enough data to form an image, the three-dimensional representations of the objects are fed into a digital reconstruction algorithm that creates a holographic map of the objects in space. The scanning system will become even faster and more accurate over time, Hall said. How the system works can be seen in this video:
Grigory Matyukhin