Recent events have shown how much high-speed, ubiquitous and equitable internet access is vital to our economy, lives and livelihoods—and cities are responding with Fiber to the Home (FTTH) initiatives. A prominent Colorado engineering and project services firm needed to collect pre-construction images for thousands of properties for a large-scale FTTH project. To meet this challenge, they chose mobile imaging to capture georeferenced time-stamped images used to manage potential construction-related claims.

It was a matter of scale. The vibrant City of Loveland, Colorado with a population of 78,000, has begun construction of the Pulse system that will deliver highspeed internet to every business and residence in the city. With multiple contractors installing fiber by direct bury and directional boring, the project represents more than 30,000 individual construction sites.

“In this project we find risk management exponentially more difficult, because we are not just dealing with the single owner and site where we can make sure damage does not occur—we’re dealing with an entire city,” said Joshua Ooms, project engineer with Ditesco, the Fort Collins, Coloradobased project management, construction management and civil engineering firm tasked with coordinating multiple contractors on the Loveland FTTH project.

To help mitigate risk to contractors and owners pertaining to construction-related damage, today’s firms provide preconstruction photos. “We broke up the city into 200 sites, each about the size of a subdivision,” said Ooms. “To walk each of the thousands of properties, take high-resolution photos and index them, would have taken months. Mobile imaging was our only practical option.”

TIMELY CAPTURE

The citywide project was broken into five sections for a phased execution. Based on recommendations from Frontier Precision, Ditesco selected the Trimble MX7 Mobile Imaging System for the imaging work. Building on training and set-up assistance from Frontier, Ditesco used the MX7 on each phase, keeping the date-of-image capture as close to the actual construction window as possible.

“Rather than having to spend weeks canvassing thousands of properties in each section, we have been able to drive some sections in a single day,” said Ooms. “And once processed, we are able to search for images quickly by street and address, look at features from multiple perspectives, and take measurements directly from the images.” The MX7 is small, light and compact enough for one person to install on any vehicle with a roof rack. Installation and operation are browser-based, so the MX7 can be operated on a tablet and an intern can be trained to use it on site.

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The Trimble MX7 is easy to mount on conventional vehicles.

Precise georegistration of the images is achieved with the built-in Applanix AP-15 integrated inertial-GNSS system. The images are positioned and oriented during processing in Applanix POSPac MMS and Trimble Business Center software.

RETURN ON INVESTMENT

The project realized benefits almost immediately. In one situation, a landowner suspected that a crack in the retaining wall at the edge of the right of way was the result of the directional boring done by one of the contractors. The time-stamped images showed clearly that it was a structural crack that existed prior to construction. At another site, a faint crack in a concrete driveway, visible in the high-resolution images also proved to predate construction.

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Pre-construction photos document existing cracks and heaving in a residential area.

Ooms notes that even a few of these claims, were it not for the images disproving liability, might have ended up costing more to repair than the entire cost of the image capture for a project section.

Ditesco also utilized Trimble R2 GNSS rovers and tablets to perform as-built surveys of the installed fiber and enclosures. And Ditesco was able to implement an in-the-field workflow where issues are mapped and reported to the respective contractors to fix, streamlining the typical time-consuming punch list process while avoiding expensive change orders.

GEARING UP FOR GROWTH 

Ditesco intends to continue using mobile mapping for future FTTH projects, as well as pre-design and as-built surveys for other civil engineering projects. Loveland is one example of how FTTH is catching on for municipalities, including nearby Fort Collins and elsewhere in the country and around the globe. And for FTTH to spread rapidly, engineering and construction efficiencies like those the Trimble MX7 provides will be essential.

“To walk each of the thousands of sites and take high-resolution photos and index them would have taken months. The Trimble MX7 was the most effective option.” — Joshua Ooms, Project Engineer, Ditesco


About the Author

Trimble-Geospatial
Trimble Geospatial

Trimble Geospatial provides Land Surveying, GIS, Scanning, Mobile Mapping, Remote Sensing, Photogrammetry and Forensics professionals with industry leading hardware and software solutions.