Understanding GPR And How Radar Waves Work


Ground penetrating radar, or GPR, looks like magic when you see it in action.

GPR is a technology that lets you see through solid objects, and it is used to locate pipes and utilities underneath concrete.

In some ways, it is like an x-ray, but unlike x-rays, the technology behind it is not dangerous radiation.

GPR uses radar waves as a way of ‘seeing’ when you cannot use normal vision and light.

It relies on high-frequency radio waves to give an insight into things that are far away from us or hidden under the ground.

How Does Radar Work?

Radar technology uses radio waves, which are produced using a magnetron.

These radio waves travel just as quickly as light waves, but the wave is longer and has a lower frequency.

We cannot see radio waves, yet they can pass through a lot of objects, which is what makes them so useful.

Ground penetrating radar passes through concrete and soil and bounces back to the sensors when it hits something that refracts the wave.

GPR can give high resolution, detailed images up to about two feet deep, and can penetrate much deeper, up to 100 meters, in gravel although the image produced in that case would be less detailed.

What Blocks or Refracts Radio Waves?

When a radio wave hits an object, some of the power is reflected, and some of it is absorbed, while some passes through the material.

Which of those happens, and how much, depends on the type of material.

Most metals will reflect almost all of the power of the wave (which is how pipes are identified), while glass would let almost all of the power through.

The amount of energy absorbed is known as the attenuation coefficient. Most building materials, including concrete, let radio waves pass through them.

Copper, on the other hand, can absorb radio waves.  Water can also absorb radio waves.

How Can We See Objects That Don’t Refract Radio Waves?

Ground penetrating radar works by identifying when there are changes in the rate at which a signal is bounced back.

It is easy to spot metal pipes because they refract the waves, so they are bounced back to the sensor quickly.

Plastic pipes and other objects that do not refract radio waves are harder to spot, as are natural voids, but they will show up on the radar.

Technicians can identify such anomalies because the scan is conducted orthogonally, and there will be differences in the rate of refraction as you move across the void.

This makes it possible to identify subsurface voids, plastic water or gas pipes, and other anomalies with relative ease.

Are Radio Waves Safe?

Radio waves, especially the kind that are used for GPR, are safe.

The technology might sound scary, but radar uses radio waves which are on a different part of the spectrum to harmful radiation.

The signals that are emitted are only around 1% of the power of a mobile phone signal, so if you are comfortable using your phone you should feel completely comfortable using GPR.

You can even use your phone and other electrical appliances around GPR equipment without fear of the GPR interfering with the device or vice versa.

As long as your electronic devices are properly shielded (which undamaged consumer-grade devices should be), then there is nothing to worry about.

GPR is safe, efficient and easy, and will give you the information you need to plan your construction or repair work, avoiding any utilities or objects under the ground.

If you have any construction or excavation projects on the go, it is vitally important to hire a concrete scanning company to scan the location first.

High Resolution Concrete Scanning is a company you can trust to provide you with the most accurate and detailed information when it comes to scanning your concrete structures.

They have years of experience and use the most advanced tools and equipment in the business.

At High Resolution Concrete Scanning, our specialisation in concrete scanning services has made us industry leaders. If you need to perform any type of concrete scanning, then look no further than us at High Resolution Concrete Scanning.

Please call us today on 0437 365 830 or contact us through our website

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