New utility scanning technology is now available that adds to the professional utility contractor’s toolbox. The new technology uses sensor fusion, in which coils that detect power radiated from electrical cables are fused with ground-penetrating radar (GPR) in a single box. This new system produces an overlay over radar data that shows the presence of powered electrical cables. This integrated capability is invaluable for the smaller electrical contractors, utility installers, and gas and water utilities, as well as towns, municipalities, and states tasked with locating and marking underground utilities.
Creating a more affordable GPR device for the utility locating market required a complete product redesign. The goal was to develop a simple to manufacture package that would maintain the excellent performance and ruggedness associated with higher end utility scanning equipment.
The affordability factor was a primary motivator for Peter Doyle, technical sales manager for Detection Solutions, a reseller and distributor of GPR products based in Australia. “The importance of an affordable unit was immense for the customers we deal with,” said Doyle. He adds, “Now, some customers will be able to get that second or third system to complete more jobs.”
Mark Johnson, market manager for Ground Penetrating Radar Systems Inc. (GPRS), also cited the affordability factor as a big plus. GPRS is the nation’s largest company specializing in detection of underground utilities and scanning of concrete structures. “The more affordable the equipment, the sooner we can put a new guy in the field and continue to grow the business,” said Johnson.
In the past, use of consumer-based controller components had always been hampered by the need to charge them using a (somewhat flimsy) cable plugged into the back of the device. Since GPR systems are frequently used in field environments – typically dusty, wet places – the normal USB cable would not hold up.
The team decided to implement a wireless design, completely eliminating the connector issue. The Wi-Fi was designed to handle the data rates encountered, and rugged enough to satisfy the needs of customers pushing these machines through dirt. Also included is a backup wired connection if Wi-Fi is not allowed on a particular site or facility.
Other goals included making the design bomb-proof, as well as impervious enough to water and dust so it could receive an IP 65 rating. Another goal was making the unit portable, so it could fold down into the back of a small car, or even be stowed in an airplane overhead compartment.
The device is equipped with four small wheels designed for use on concrete, asphalt, or compacted dirt. It can also be used with a larger cart that can operate in uneven surfaces and over large rocks.
Innovative design features sensor data fusion
The internals are where the new GPR system really shines. The antenna design is based on an existing 350 MHz digital antenna, using patented HyperStacking technology that allows users to see deeper targets and operate in conditions considered too “noisy” for conventional systems. The design uses less power, which allows the battery to run the system for more than eight hours.
The system design also includes LineTrac™ technology, which helps locate specific power sources underground. Coils that detect power radiated from electrical cables are fused with standard GPR radar into a single box in a method called sensor fusion. This produces an overlay over standard radar data alerting users of the presence of electrical cables.
The system’s tablet provides a direct connection with a user’s GPS system. Software to communicate with the GPS system is provided using Bluetooth technology.
The unit is also equipped with an intuitive user interface. For example, the software balances the data brightness (data gain) no matter what happens with ground conditions. Real time algorithms constantly balance this data when users go from wet to dry ground, or from pavement to sodded lawn or dirt. This makes it easier and quicker to find targets, like utilities or pipes.
In the field with the new technology
Doyle says the new technology is a perfect size and the wireless antenna is a great functional feature, since fewer plugs can be damaged or broken. “The new interface is user friendly and easy to learn, making it quick for inexperienced users to navigate. The LineTrac capability can help on large jobs by identifying certain assets quickly for later verification.”
Mark Johnson of GPRS cites the small size as a major advantage. “Sometimes we get into areas where we have tight spaces. For example, I workedat a power substation where there is no more than a foot and a half of space between the concrete foundations holding up all these electrical transformers. Larger units would be more cumbersome and could be a disadvantage there.”
Traditional methods for locating utilities provide information to about 3 to 4 ft of where a target is located. The new technology shows information to within an inch of the location and can also differentiate among the utilities located in a trench.
The new technology is more affordable and provides an easier entry into the GPR market. At the same time, the system’s data fusion using multiple sensors, and easier user interface, provides an extremely high level of performance for today’s utility locators.