Novel radar technology enables ground penetrating radar scanning at roadway speeds

Underground utility damage during construction is a major safety problem and drag on economies in many countries.  The technologies that are currently considered best practices for detecting underground utilities have been used for decades and are characterized by being slow, unreliable under certain conditions and for certain types of underground equipment, and hazardous for the operator.  Lately ground penetrating radar (GPR) has been getting significantly increased attention primarily because it can detect both metallic and non-metallic underground objects, capture continuous digital scans, and because it can capture 3D position of underground objects.   Using a novel radar technology, Earth Radar has developed GPR systems that works in a different manner to traditional equipment and which can scan at up to roadway speeds.  It has been applied commercially since 2008 to detect sub surface objects on projects that include highway intersections, road pavements, urban streets, and airports. 

Introduction

The Common Ground Alliance estimates that there are 400,000 cases of utility damage during construction annually in the U.S. In the U.S. according to Federal Highway Administration (FHWA) underground utility conflicts and relocations are a major cause of project delays during road construction. A study by the Pennsylvania State University found $21 in cost saving for every dollar invested in improved location information about underground infrastructure.

Not knowing where underground infrastructure is has engendered what is estimated to be a $10 billion per year industry in the U.S. Every construction project requires locating underground utilities prior to and during construction.

The most accurate way to determine the location of underground infrastructure is to expose it by carefully digging a hole and then bring in a survey team to survey the location.  But this is time consuming, expensive, and can be hazardous.

An increasingly viable alternative is various types of remote sensing. Currently best practice for locating underground infrastructure is walking the site or right of way with electromagnetic wands (EMI) or ground penetrating radar (GPR) pushcarts. This is slow and can be extremely hazardous.  It can also have major indirect and social costs such as lane closures on busy transportation routes.

NM-GPR a novel approach to ground penetrating radar

We are beginning to see some promising advances in remote sensing technology for detecting underground utilities. Capturing ground penetrating radar scans of below ground infrastructure data at roadway speeds would be an important step toward efficiently and safely creating 3D maps of the underground.  Recently I had the opportunity to chat with Wayne Muller of Earth Radar, a company developing new forms of GPR technology based in Brisbane, Australia.  In the last few years Earth Radar has been developing and commercially using this new radar technology.  Originally reported in a talk by Wayne Muller and Bryan Reeves Application of a traffic-speed road scanning system including a new type of 3-D GPR at the NDE/NDT for Highways and Bridges: Structural Materials Technology (SMT) conference, in August 2010 in New York City, Noise-Modulated Ground Penetrating Radar (NM-GPR) is a GPR variant that uses coded signal modulation and efficient receiver hardware to enable traffic-speed data capture. It was developed in Australia by Radar Portal Systems and a first generation version was used starting in 2008 for a range of road investigations for the Queensland Department of Transport and Main Roads.

One variant, called Sparas, is a trailer based 3D GPR that mesures 30 points across a 2.5m width. It is normally configured to collecting measuremnts at 60mm intervals along the road at speed of up to 100 km/hour.  Referred to as noise-modulated or coded signal GPR (NM-GPR), the core technology us a simplified approach to radar hardware that combines many fast low-fidelity measurements to create a high-fidelty image of the subsurface. The technology is able to retain the good resolution of high-frequency antenans to greater depths that conventional GPR systems can, without using different antenna sizes. Under typical soil conditions it is capable of detecting objects in high detail down to 1.5 to 2 meters and in good conditions down to 3m.  Earth Radar has also developed UtiliVision software to assist in interpreting the scans and turning the data into 3D maps.  In a recent commercial project in the Gold Coast, these technologies were used to cover 7.5 km of highway lanes and numerous side streets in just over 15 hours of scanning. More than 2000 subsurface utilities were later detected and mapped using these measurements. 

The rig that Earth Radar typically uses is composed of a vehicle equipped with four pods containing radar antennas and protective skids positioned about a cm above the road surface. A photometric stereo imaging system is also used to sumulatenously capture above ground features.

This is the first GPR system using a novel radar technology of which I am aware that has been deployed commercially for a number of years on a range of real world projects from highway intersections to highways and urban streets to airports.  This represents a major breakthrough in applying GPR to safely and rapidly scan the subsurface without lane closures and the associated traffic disruptions.

Read more about locating underground infrastructure

Underground utility damage during construction is a major safety problem and drag on economies in many countries.  The technologies that are currently considered best practices for detecting underground utilities have been used for decades and are characterized by being slow, unreliable under certain conditions and for certain types of underground equipment, and hazardous for the operator.  Lately ground penetrating radar (GPR) has been getting significantly increased attention primarily because it can detect both metallic and non-metallic underground objects, capture continuous digital scans, and because it can capture 3D position of underground objects.   Using a novel radar technology, Earth Radar has developed GPR systems that works in a different manner to traditional equipment and which can scan at up to roadway speeds.  It has been applied commercially since 2008 to detect sub surface objects on projects that include highway intersections, road pavements, urban streets, and airports. 

Introduction

The Common Ground Alliance estimates that there are 400,000 cases of utility damage during construction annually in the U.S. In the U.S. according to Federal Highway Administration (FHWA) underground utility conflicts and relocations are a major cause of project delays during road construction. A study by the Pennsylvania State University found $21 in cost saving for every dollar invested in improved location information about underground infrastructure.

Not knowing where underground infrastructure is has engendered what is estimated to be a $10 billion per year industry in the U.S. Every construction project requires locating underground utilities prior to and during construction.

The most accurate way to determine the location of underground infrastructure is to expose it by carefully digging a hole and then bring in a survey team to survey the location.  But this is time consuming, expensive, and can be hazardous.

An increasingly viable alternative is various types of remote sensing. Currently best practice for locating underground infrastructure is walking the site or right of way with electromagnetic wands (EMI) or ground penetrating radar (GPR) pushcarts. This is slow and can be extremely hazardous.  It can also have major indirect and social costs such as lane closures on busy transportation routes.

NM-GPR a novel approach to ground penetrating radar

We are beginning to see some promising advances in remote sensing technology for detecting underground utilities. Capturing ground penetrating radar scans of below ground infrastructure data at roadway speeds would be an important step toward efficiently and safely creating 3D maps of the underground.  Recently I had the opportunity to chat with Wayne Muller of Earth Radar, a company developing new forms of GPR technology based in Brisbane, Australia.  In the last few years Earth Radar has been developing and commercially using this new radar technology.  Originally reported in a talk by Wayne Muller and Bryan Reeves Application of a traffic-speed road scanning system including a new type of 3-D GPR at the NDE/NDT for Highways and Bridges: Structural Materials Technology (SMT) conference, in August 2010 in New York City, Noise-Modulated Ground Penetrating Radar (NM-GPR) is a GPR variant that uses coded signal modulation and efficient receiver hardware to enable traffic-speed data capture. It was developed in Australia by Radar Portal Systems and a first generation version was used starting in 2008 for a range of road investigations for the Queensland Department of Transport and Main Roads.

One variant, called Sparas, is a trailer based 3D GPR that mesures 30 points across a 2.5m width. It is normally configured to collecting measuremnts at 60mm intervals along the road at speed of up to 100 km/hour.  Referred to as noise-modulated or coded signal GPR (NM-GPR), the core technology us a simplified approach to radar hardware that combines many fast low-fidelity measurements to create a high-fidelty image of the subsurface. The technology is able to retain the good resolution of high-frequency antenans to greater depths that conventional GPR systems can, without using different antenna sizes. Under typical soil conditions it is capable of detecting objects in high detail down to 1.5 to 2 meters and in good conditions down to 3m.  Earth Radar has also developed UtiliVision software to assist in interpreting the scans and turning the data into 3D maps.  In a recent commercial project in the Gold Coast, these technologies were used to cover 7.5 km of highway lanes and numerous side streets in just over 15 hours of scanning. More than 2000 subsurface utilities were later detected and mapped using these measurements. 

The rig that Earth Radar typically uses is composed of a vehicle equipped with four pods containing radar antennas and protective skids positioned about a cm above the road surface. A photometric stereo imaging system is also used to sumulatenously capture above ground features.

This is the first GPR system using a novel radar technology of which I am aware that has been deployed commercially for a number of years on a range of real world projects from highway intersections to highways and urban streets to airports.  This represents a major breakthrough in applying GPR to safely and rapidly scan the subsurface without lane closures and the associated traffic disruptions.

Read more about locating underground infrastructure