Looking through walls using WiFi

Roberto Saracco June 27, 2017 Blog 761 Views

Using two drones to scan a closed environment with WiFi to look through the brick walls. Credit: UCSB

Electromagnetic signals have been used for quite a while to look through solid surfaces, including looking through our skin to visualise internal organs in the body. The possibility to use WiFi to look through a wall is also nothing new, there was an article in 2012 reporting the result of a research at the University College of London and I remember seeing a similar system at MIT.

Now, I stepped onto an article explaining the possibility of using drones equipped with WiFi radio to scan a wall and using the resulting data to see through the walls.

Researchers at the University of Santa Barbara, California, decided to use two drones and have they flying in a coordinated mode. The first drone creates a WiFi field and moves along the wall of a constructions (made of bricks, but ic can be made in any materials that does not shield the interior from the electromagnetic field), following a predetermined path, basically scanning the construction, and the other drone overing on the other side of the construction detects the changes in the electromagnetic field. These variations are sent to a computer where an application processes them and creates a rendering of what is inside the construction.

The actual content in the construction and the rendering created through the analyses of the WiFi field variations. Credit: UCSB

As you can see from the image, the rendering is not like taking a photo, it looks more like a radiography (which is what it is!). It might seem pretty crude, yet it provides information on what the inside looks like.

I wouldn’t be surprised if something similar will come to my smartphone in the coming years. I am already using it to measure objects, to check on my pulse, to make sure that a frame is level… why not having the possibility of using it to look across a wall? Yes, I appreciate that other people’s smartphones would be able to look through my walls as well and indeed, that would be a problem… not to mention the support it would provide to a thief in confirming no one is at home.

I can’t think of a single technology that has only upside and no downside. May be the problem is “us”, not the technology…

You may want to take a look at the clip showing how it works.