3-D GPR array makes it easier for contractors to identify what is buried underground.
IDS GeoRadar has found a new way for contractors to map underground utilities and features. The company’s Stream C will give those using it a clearer picture of what is underground, in a unique perspective.
The array of 34 antennas in two polarizations enables an accurate 3-D reconstruction of the underground utility network to be created in a single scan.
“It provides instantaneous images that are much easier to understand than a standard GPR,” says Dan Broekhove, business development technician for IDS GeoRadar. “Anyone can understand looking at a 3-D image going up and down through it. It’s a little harder looking at a side slice, which is what a typical GPR device does.”
Unlike other GPR units that require the contractor to do X-Y grids to get a clear picture of what is underground, the Stream C surveys only need to be performed in one direction to ensure optimal detection for both longitude and transversal pipes.
“Everything is GPS coordinated as well, so if you find a pipe or target, it’s accurate down to less than one inch on your X and Y coordinates, and the machine is accurate to about 1 to 2 inches as far as depth,” Broekhove says. “It’s way more accurate than a wand, which has an average room for error from 1 to 4 feet.”
The Stream C, weighing just 165 pounds, can be folded up and transported via pickup truck or van. If there is no device to help with lifting, two workers can move it by hand. The unit is about the width of a residential sidewalk and can be folded up for transport.
The company says it’s easy for a contractor to learn how to use the Stream C, saying it is easier than training someone on an entry-level GPR system. “With the entry-level GPR units, you’re looking at a cross diagram showing waves and it can be scary,” Broekhove says. “On these machines, on the display, you would have a top-down topographic view of what you’re looking at in 3-D. It’s a lot easier to determine if you have a pipe rather than looking at waves and trying to figure it out. The 3-D is a lot easier to interpret than the 2-D stuff.”
The unit is designed for any contractor doing subsurface work — especially those working with gas or sewer lines. The Stream C also makes it easy for contractors to provide customers with a fallback option if marks on the road are washed away by rain.
“With the mapping feature, it saves your marks for later,” Broekhove says. “It saves all of your targets so you can go back and georeference. You can locate the pipes again just by using that target you already had, and it’ll be right there and you can trace it all the way back.”
Contractors using the unit can also create a report on the spot.
“So if you just put in a new line for a customer, you can go map that project and give them a report in about 30 minutes,” Broekhove says. “You can put it straight on a flash drive and give it to the customer right from the device, or connect it to a wireless printer in your truck.”
PICKING UP STEAM
Broekhove is excited to see where the company’s unit will go. The unit hit the market in September 2016.
Italian customer Technics used the Stream C in January when the company was hired to undertake a GPR survey in the north and west buildings of Lincoln Cathedral in the U.K. to identify subsurface information on the scale and location of services and buried archaeological features on site.
Data was collected and is being used to assist in the development of a strategy to minimize any damage to buried archaeological evidence that may occur from the construction of planned refectory and visitor facilities, as well as map known and unknown buried services more precisely than existing documentation.
“It’s exciting to see how contractors are going to be using this and we’ve kept it at a reasonable price compared to some other devices that can do similar things,” Broekhove says. “It makes it safer for those doing the digging out there.”