IDS Opera DUO GPR for Utility Locating
NDT Concrete owns and employs an IDS Opera DUO, the state-of-the-art GPR system for utility locating. Besides, we are proud to be the official distributor of IDS GPR products in the state of Florida. In the following, we will explain to you the main features of Opera DUO GPR system. Obviously, our expectation is that you will see why it is our equipment of choice and maybe yours in the future.
1. How is Opera DUO designed?
As you can see in Fig. 1 and Fig. 2, Opera DUO comes with 2-wheel and 4-wheel versions. However, it should not be of much concern because although the two appear slightly different, they have exactly the same functionality. Specifically, for both systems, only the two wheels on the back encode the travelling distance. That is to say, the two front wheels added are simply for the ease of maneuvering the machine.
Opera DUO Specifications
2. What is its biggest advantage?
While you have seen many benefits from the design of Opera DUO, we want to emphasize here the biggest advantage of the system. To start, we need to recall a fundamental principle of GPR, which identifies the trade-off between radar frequency and the detected resolution. To be specific, scientists have had the following observations. The first is a low frequency radio wave penetrates deeper into a medium than a higher frequency wave does. However, the second is that a low frequency GPR antenna compromises the detection of small or clustered objects on GPR images.
What the above mean is we cannot obtain a big detection depth and a high image resolution at the same time. Fortunately, IDS has come up with the finest design to solve such a problem. Specifically, they include in the antenna box two hardware channels. One has a central frequency of 250 MHz and that of the other is 750 MHz. So with one device, we can detect not only small objects near the surface but also utilities and structures deeper in the earth. For comparison, to obtain the same amount of data with a traditional GPR system, you will have to double your efforts and more. First, you have to scan the same survey grid twice. Second, you need time to change the antenna between those two scans.
3. Example Results from Opera DUO data
3.1. Detection & subsurface imaging of septic system
In the below figure and video you can see how well NDT Concrete detected and imaged an underground septic system with Opera DUO. Specifically, you can see on the plan view and the 3D image both the tank and the drainfield of the system. Furthermore, you can compare our results with the sketch obtained from Florida Department of Health. As another piece of information, it took us approximately one and a half hour to collect the data for this example. With respect to data processing, using our proprietary computer program, it took us 5 more minutes to generate those results. As such, for your project, we can deliver the report very quickly.
3.2. Detection and subsurface imaging of water main
We also used Opera DUO to locate water main pipe for the same property as above. Likewise, our results are presented in the following. As you can see, the plan view and 3D images clearly show the water main location. In addition, you can also observe the concrete driveway.
