Florian Euchner is a student at the University of Stuttgart in Germany and he recently put up a video on his YouTube channel detailing his recent radio experiments. In it, he shows how by using a matrix of low-cost ESP32 modules, he was able to measure the delay and amplitude of some microwave WiFi signals and with some very clever software, he was able to display this on a screen. In a way, his method allows users to 'see' where radio signals at 2.4 GHz are coming from.
In the screenshot above, the direct Wi-Fi signal from a phone can be seen as well as a reflection on the left is from a metal screen.
What was really impressive was the ability to 'see' radio waves through something that is probably a wall made from plasterboard. As long as radio signals can pass through then they can be 'seen'.
Another interesting aspect of the experiment was how the radiation pattern from an antenna was 'visible'.
The video can be seen below...
Link...
1) Florian's website... https://jeija.net/
