The past year has seen imaging technologies emerge as important tools for positioning and measurement. Once the realm of specialized photogrammetric technicians, instruments and software, visual data is becoming an increasingly common component of geospatial information. This rapid acceptance is not simply the result of early adopters latching onto a new technology. Much of the momentum is coming from fast payback and the potential for long-term savings. Whether it comes from terrestrial cameras or unmanned aerial systems (UAS), imaging is making a strong financial case.
There are several techniques for gathering visual data. On the ground, calibrated digital cameras integrated into robotic total stations provide “see what the instrument sees” images tied to precise positions. New solutions such as the Trimble V10 Imaging Rover use multiple cameras to collect 360-degree panoramic images. The imaging rover can operate standalone or integrated with GNSS receivers or prism targets to produce georeferenced images. In the air, the capabilities of UAS as a cost-effective imaging solution are well known.
Efficiency and Flexibility in the Field
It’s faster for a field crew to collect a handful of images than to collect dozens, often hundreds, of individual 3D points. In the time needed to capture a single point using
|A Trimble V10 imaging rover integrated with a Trimble R10 GNSS receiver captures georeferenced panoramic images of complex sites and facilities. Imaging reduces the need to enter hazardous or restricted areas.|
RTK or a robotic total station, a crew can use a Trimble V10 imaging rover to collect a digital panoramic photo of a scene. By collecting a few, well-planned images, a crew can capture data that can produce a detailed 3D description of a project site. The time savings are impressive.
For example, in preparing a bid to collect locations of vegetation and improvements along a waterway, a Florida survey firm needed to develop detailed estimates of field time. Working in an area that is not always conducive to RTK, the surveyors used total stations as well as GNSS. This complicated the estimates, as there were many cases where the field crews would not know what was needed until they arrived at each site. Things changed significantly when the company added a Trimble V10 to the mix. Instead of walking to each object with an RTK rover or prism target, the crews could capture the needed information by taking photos from a few carefully selected locations on each site. In many cases, they completed in minutes work that might have taken an hour or more. This story is not unusual—it’s common to hear of productivity increases of 30 to 40 percent when using imaging for field data collection.
With significant productivity improvements in the field, it’s reasonable to ask about the tradeoff in terms of data processing in the office. Do we give back much of the time saved? The answer is no. In fact, imaging and visual data can deliver additional gains in overall office throughput.
New Sources for Measurement and Modeling
It’s true that some of the time saved in the field is offset by time in the office. But because much of the office processing is automated, it can greatly reduce the time and effort needed to process images into useable visual datasets. The work is integrated into existing office software, so there’s little need for additional training or technical expertise. And once the field imagery is integrated into the project dataset, technicians can measure additional points from the photos—attaching feature codes, attributes and linework with the same tools used for conventional point-based data collection. The storied concept of “survey in the office” is now a reality.
For example, a technician can use Trimble Business Center software to compile point data from GNSS RTK and optical surveying systems. The same software can process image data from Trimble VISION™ technology built into the total stations as well as panoramic images captured by the Trimble V10. It can also incorporate aerial imagery captured by the Trimble UX5 aerial rover and use the images to compute new 3D points.
The ability to combine images from imaging rovers, total stations and UAS provides enormous flexibility to the geospatial professional. For example, a ground team can measure the edge of a building roof using an imaging total station or imaging rover. A second image, taken from a UAS, can be combined with the ground data to provide the information needed to compute the 3D location of the point. It’s also possible to combine imagery with directly measured points (collected with GNSS or total stations) to provide quality control and checks on accuracy and precision.
Imaging becomes even more valuable in projects that require a high level of detail. Instead of using a field crew to locate individual points, the work can be done by a single technician in the office. Once the points, lines and features are created, they are easily shared with other software including CAD, GIS, enterprise management and specialized design and analysis applications. The bottom line is clear: even with conservative estimates on office processing, imaging delivers impressive gains in overall productivity.
Adding Value with New Deliverables
To this point, we’ve mainly looked at using imaging for gathering data for surveying and mapping, engineering, construction and related activities. But the new tools for visualization are well suited to an array of applications where images and positioning can combine to produce accurate and highly detailed 3D information. The result is new deliverables that can be used in some exciting ways.
One example is in the inspection, maintenance and management of complex infrastructure. Imaging rovers can radically reduce the time and cost for on-site inspections of industrial assets, bridges and civil infrastructure, oil and gas facilities, and utility installations. In addition to providing data for direct measurements, the images provide visual access to stakeholders who normally would not visit a site. The visual data provides additional detail and helps experts to make informed decisions on maintenance, repair and upgrades.
A second example is forensic applications such as crime and accident scene investigation and re-creation. It’s common for police officers to use total stations or scanners to document a scene. Imaging rovers are much faster and easier to use—an important aspect for officers not familiar with positioning technologies. By using imaging rovers or total stations, scenes can be cleared and reopened in much less time. This is especially important in highway accidents, where lengthy road closures during accident investigation introduce significant cost and safety issues.
These examples illustrate perhaps the most valuable benefit of visual data—the ability to deliver additional information at no additional cost. In the forensics example, even after an accident scene has been cleared, the images provide investigators with reliable sources of evidence and measurement that otherwise would be lost. In any application, it’s easy to identify and measure points that might otherwise be missed or to collect additional information that was not originally requested. And it all can be done without sending a crew back to the field.
New Technologies Produce New Business
As geospatial professionals, we know that we need to understand how our clients use the information we provide. By combining this understanding with the flexibility and speed of imaging technologies, we can grow our businesses through the addition of new value and services to clients and stakeholders.
We’ve seen that imaging can transform the work in both field and office. And while imaging provides exciting ways to cut costs and add value to your services and deliverables, it’s just one of multiple technologies available for geospatial applications. It remains essential to select and utilize tools that are most appropriate for a specific client or project. The performance and flexibility of imaging and vision systems make the choice easier.
|The Trimble UX5 Aerial Imaging Solution can collect visual data from low altitude to produce high-resolution photos. Images can be combined with terrestrial photos and 3D points.|