Can Technology be Used to See Through Walls?

Curious about if anyone can just see you going about your life in your own home? Read on about current technologies that are used mostly for tracking and imaging to see how safe you really are.


Here are answers to common questions about current technologies and if they can see or penetrate walls.

Can Sonar See Through Walls?

Sonar is not effective at penetrating walls made of solid objects because the sound waves do not travel well through the vibrating particles that make up solid objects.

Sonar works by emitting sound waves underwater or air and then interpreting how those waves bounce back into the receiver which then produces an image of the landscape.


Can Radar See Through Walls?

No. Radar cannot see through walls with any real accuracy because the beams spread when they hit solid objects, which can create false positives. Also, walls can absorb radar waves depending on what material they are made of.


Can Radio Waves See Through Walls?

No. Radio waves are not effective at seeing through walls because the waves spread in all directions when they hit solid objects which makes it difficult to see an image. Also, radio waves easily bounce off of substances like metal and glass making it hard to tell what is an object and what is part of the background.


Can Lidar See Through Walls?

No. Lidar, or Light Detection and Ranging, emits pulsed laser light which is then reflected from objects. The system calculates the time it takes for the lasers to bounce back to determine a distance based on the speed of light.

The beams spread through solid objects making it hard to see an accurate image. Also glass and metal absorb LiDAR making it hard to differentiate between objects and the background.


Can Thermal Imaging See Through Walls?

No, you can not see through walls with thermal imaging. Thermal imaging works by detecting infrared radiation emitted from objects and converting the signal into a thermal image, where different temperatures are represented with different colors or shades of grey.

A thermal or infrared camera will only be able to detect heat from the wall not what’s actually behind it. So if something were inside the wall, like missing insulation and caused a big enough temperature difference that would be picked up on a thermal camera.


Can X-rays See Through Walls?

No, X-rays cannot see through walls at all. This is not how technology works.

X-ray imaging is the process where something is radiated with a specific energy range of electromagnetic radiation. Then you look at the shadow of the radiation on the other side. Think of X-ray imaging as like shadow puppets. The light is the source, and the hand puppets being used will block the light to form the shadow.

The image that you would get would be very difficult since the wall would most likely be one of the most radiopaque items in the path and will just absorb most of the X-ray thus creating the strongest shadow.


Now that we know of all the technologies that can’t see through walls let’s look at something that is being developed and has the most potential. Range-R radars.


What are Range-R Radars?

Range-R radar devices are handheld or mounted on a pistol. The device emits a pulse of waves in the direction it is pointing, when the waves come into contact with the wall they bounce back. The radar device calculates how long it took for the wave to reflect back in order to determine the distance between the device and whatever is on the other side of the wall.


Can Range-R Radars See Through Walls?

Range-R radar devices are the closest to being able to see through walls. Range-R radar devices pinpoint the location of a person based on sound waves that bounce back from a hand-held device. They can see sounds made by a person’s movement through a wall because the ultra low-frequency radiofrequency waves reflect off any objects in its path, but the device only measures distance and not what is beyond it.


How Accurate is Range-R Radar?

Range-R radars are accurate to within +/- 3 feet. If the device is moved it will give a different reading because the radio waves bounce off of other objects, which can create interference or false positives.


What Are Some Issues with Range-R?

One issue is that the device only works if it is pointed directly at someone and doesn’t work so well if there are multiple people in the same vicinity.

Range-R has also come under fire about whether or not it violates Fourth Amendment rights since it can detect what’s happening inside homes if police are standing outside with the device.



Radar devices, like Range-R, are the closest to being able to penetrate through walls but are still lacking in what is usually dreamt up when people think about seeing through walls. The only way to see inside a structure with a wall is if someone on the other side opens a door, window, or goes outside. So we have to rely on good old-fashioned human vision for now. No X-ray glasses yet.