Utility detection, especially utility mapping, is a cost and labour intense application. Detecting utilities and mapping them require more investment than just topographic surveying. Still, having accurate maps of utilities has great value for various stakeholders from governments to contractors.
The importance of having maps of utilities and the big effort to create these maps, brings the need for increasing efficiency. If we look at the traditional way of mapping utilities, it consists of the following steps:
- Gathering the available maps of utilities
- Looking for evidence of buried utilities like manholes, light poles, tarmacs
- Opening manhole covers and finding the direction of pipes and type of utility
- Scanning the area with electromagnetic locators and marking the detected cables on the surface
- Scanning the area with Ground Penetrating Radar (GPR) and mark the interpreted utilities on the surface
- Recording the points using a TPS or GNSS after the detection to complete the marking
- Converting the points collected by the TPS and GNSS to lines on a CAD software
One alternative to this long workflow is using post-processing software for the GPR data. Post-processing can be done in the office to reduce the time spent on site, however, the person in the office will not see the surrounding and will miss the physical evidence of utilities. With smart solutions, we can make this steps more efficient and even merge them into one.
Existing maps can be provided by the utility owners, normally these maps are printed out to be handed over to the field crew. With Leica DX Manager Mapping, maps can be downloaded to your tablet. This central dashboard solution is easier than using paper maps on the field, and if the downloaded maps are geo- referenced they can even be located on the field by using DX Field mapping.
DX Manager Mapping solutions allow users to:
- Record the features on the field such as manholes or street lights
- Take photos of the features and link them to their geo-referenced location
- Open the manhole covers, take a photo of it and edit the photo and write the necessary attributes on it.
- These steps also make mapping and post processing at the office easier and more efficient.
In order to be more efficient when mapping utilities, you can merge the detecting and point recording steps into one step by using DX Field Mapping and a Leica Ultra with a Leica Zeno20 as you detect the utilities. When the Leica Ultra detects a cable and gets the signal high enough to make a depth measurement, DX Field Mapping users can simply record the locator point which belongs to the power cable with the coordinates and the depth. This means, in one step the detection, coordinate recording and the attributes will be saved to the cloud.
Using a Ground Penetrating Radar is often complicated for users as this requires data interpretation of Radar graphs. With the Leica DX Office Vision post-processing software, the data processing is simpler and more efficient. The processed data can be exported into a 3D DXF format and merged with the background map easily reducing the time on the field and increasing efficiency remarkably. Leica Detection Solutions provide the necessary data to create digital maps of utilities. By eliminating marking on the surface, reducing the time collecting the positions, and using post processing software, you can reduce your effort by up to 80 per cent.
How to choose the right GPR technology for my project?
Efficiency is not only data-collection related; it is using the right product for each application to increase productivity. Thanks to Hexagon’s product offering for detection, you can choose the right product for your application.
The size of the area to be scanned for utility detection has a big impact on the product choice. The nature of ground penetrating technology requires making multiple scans side by side to identify continuous pipes or cables. Mainly we can talk about two types of channel design for GPR technology:
- The most common type is a single channel GPR like the Leica DS2000, which means with each scan detection will be performed for one swath line.
- The other type is array systems, which has multiple channels side by side in the GPR antenna, which means with one scan, the GPR will collect data from multiple swaths. This is equal to use multiple GPR products side by side at the same time. The array system also has the advantage of having small space between channels, increasing the resolution of the detection.
For small areas like 20 metres to 20 m or smaller, a single channel GPR would be sufficient as the time to make the detection will not be too long and it will be easier to transport the unit and access narrower spots.
If the area is large, like scanning a big parking lot or an entire street, an array system GPR, such as IDS StreamC is the correct choice. Users can complete the scanning of large areas in a shorter time. Although array systems can be used for smaller areas, these products are bigger and heavier, and logistically this will not make sense for a short time of usage and will be difficult to access narrow places like narrow footpaths or between cars.
Increasing efficiency can be provided by offering the right solution, Hexagon offers the right solution for detection applications by combining different type of detection products, software solutions and positioning products to cover various applications at various locations for the convenience of users.