The Rise of Survey-Grade Positioning by way of Smartphone
The surveyor’s field notebook isn’t going to go away any time soon, but as tools advance, the role of paper and pencil will be replaced by the same devices that are changing our personal lives. That's the view of Andy Beckerson, director of business development for Korec, a UK-based provider of surveying and geospatial solutions. Beckerson says that while pencil and paper have persisted as the preferred tools for field data collection in many industries, the Bring Your Own Device (BYOD) scenario is increasingly able to penetrate the resistance and has produced colossal expansion in digital data collection. The ubiquitous smart phone, which has taken over more and more of the daily chores for consumers, has come to the workplace and even into the field with land surveyors because of what application developers, service providers and hardware manufacturers are doing to bring together geospatial technologies and users.
Broadly speaking, BYOD refers to the use of what might be consumer-grade devices as an interface with highly sophisticated tools through an application on a mobile device — a smartphone or tablet. What makes this significant for land surveying and geospatial professionals is a new development with the potential to improve — and disrupt — the use of geospatial information for users both in the commercial and consumer arenas.
From GPS to Smartphone
No one anticipated how one tool could change so many lives in such a short time. But it happened; geospatial technologies — led by GPS — are now in the hands of millions of users.
GPS first appeared on a mobile phone in 1999. Since then, GPS has become interwoven with smartphones and tablets. The Apple iPhone 3G, introduced in 2007, was the first smartphone to incorporate a GPS receiver. Fueled by Apple’s strong support for third-party developers, the 3G opened the floodgates for new ways to use geographic data. As applications developers embraced the new capabilities, the concept of location-based services quickly took hold. Today there are thousands of smartphone and tablet apps that use location data supplied by the device’s built-in GPS receiver.
But the location apps quickly run into some frustrating limitations as professional users like land surveyors push for more capabilities. One of the biggest concerns is the accuracy and reliability of GPS positions. Even in good conditions, consistently achieving accuracy of better than a few meters is beyond the capability of consumer-style smartphones. It’s challenging for the many developers and users who understand how higher accuracy can increase the performance — and value — of location-aware applications. But the cost and complexity of high-accuracy GNSS solutions have presented barriers to entry for many potential developers and their customers. The barriers are coming down.
In late 2016, Trimble introduced a software-defined GNSS receiver, Trimble Catalyst, that works with selected Android mobile handhelds, smartphones and tablets. The software-defined GNSS solution includes software running on the handheld, a small digital antenna and a subscription to the Catalyst service. With Catalyst, users can obtain positions in real time with accuracy ranging from meter-level down to centimeters.
Software-defined GNSS receivers have been on the minds of academics and developers for a decade or more. But only recently have the technological constraints been overcome. According to Rachel Blair Winkler, Trimble business area manager, Mapping & GIS, Catalyst represents a convergence and evolution of multiple technologies. Advances in processing power of small devices, highly efficient computing algorithms and development of cloud- or satellite-based correction services have reached the point where it’s now possible to produce a precise GNSS solution on a consumer-grade device. That smartphone in every surveyor’s pocket can become the interface to a precise GNSS position.
To use Catalyst, the user connects the small DA1 antenna to the smartphone or tablet using a supplied cable. The DA1 is powered by the phone and contains a patch antenna and analog-to-digital converter. It has a standard threaded connection and can be easily mounted on a pole, backpack or other mounting option. The antenna delivers raw observation GNSS satellite data to the smartphone, where it is combined with correction data from the Catalyst subscription service. Users can choose the level of precision. Subscriptions are available at different price points for meter, sub-meter, decimeter and centimeter RTK accuracies. Winkler explains that subscriptions are offered on a monthly basis, so users don’t pay for unneeded service or precision.
When it comes to the user interface, applications developers can use the Trimble Precision Software Development Kit (SDK) to access Catalyst functionality. In addition to managing the software-defined GNSS receiver to produce accurate location information, the SDK enables applications to use positioning metadata such as accuracy estimates and satellite information. Because the SDK can link to any application running on the smartphone or tablet, developers can incorporate accurate positions into existing user interfaces. The developers can then leverage their own domain expertise to produce solutions precisely tailored to specific customer tasks and workflows.
“Catalyst is putting high-accuracy, low-cost, on-demand services in the palm of everyone’s hand,” Winkler says.
New Users, Directions
Some clues about the impact of software-defined GNSS can be seen in the experience of organizations that are already working to put the new technologies to work. Catalyst will support Trimble TerraFlex software, a cloud-based mapping and GIS field solution that operates on a variety of Android devices. Companies that use TerraFlex, which is highly customizable, will be able to achieve high-accuracy positions when needed. For other operations, they can operate at lower precision — and lower cost — while using their existing forms and workflows.
Trimble is also supporting third-party developers working to adopt the Catalyst approach. One example is Atlanta-based TerraGo, which provides field data collection solutions for customers in industries including utilities, local governments, military, environmental and natural resources. The company created the first PDF-based maps and pioneered the work of putting digital maps into the hands of non-mapping experts. Today, TerraGo provides customizable mobile platforms for field data collection. The solutions run on BYOD platforms including smartphones and tablets, and often rely on the device’s built-in GPS receiver for basic positioning. Mike Gundling, TerraGo vice president for marketing and product management, explains that many TerraGo clients recognize the value of increased precision. “Accuracy is addictive,” Gundling says. “In many cases, knowing an asset’s location to within a decimeter or so can save time and money in maintenance, repairs and lifecycle management. If you can get centimeter accuracy for nearly the same price as meters, why bother with meters?” In order to provide the needed accuracy, TerraGo software can connect to external mapping or survey-grade GNSS receivers.
Gundling says users are happy with the higher accuracy, but the additional cost and more complex workflow of an external receiver can be a drawback — especially to the many TerraGo users not skilled in geospatial techniques. The cost concerns can grow when clients field a large number of field technicians who occasionally need decimeter or centimeter precision. “Our clients don’t want to switch to a different approach when they need higher accuracy. The subscriptions act as a pay-as-you-go service, which is a popular way to manage costs and access.”
That reaction is echoed in the U.K., where Korec also develops and sells its own solutions for GIS data collection. Korec’s director of business development, Andy Beckerson, has already noted that the BYOD scenario is able to penetrate the resistance and produce expansion in digital data collection. Beckerson says by alleviating concerns on accuracy, software-defined GNSS will bring new users to the world of high-precision positioning. “We can write new or customized software,” Beckerson says. “It’s very easy to build solutions that incorporate high-accuracy locations.”
Going Beyond GIS
A New Zealand firm is going a step beyond GIS data collection. Auckland-based Augview is blending positioning with 3D modeling to produce in-field augmented reality. For example, many utility companies capture the location of their assets during construction and inspection.
Augview can load the as-constructed data from a utility or municipal GIS database to a tablet or smartphone. Using position and orientation from onboard sensors, Augview can superimpose the location of underground utilities onto a georeferenced view of an area as seen by the device’s built-in camera. The solution enables field workers to visualize otherwise invisible objects.
Accuracy is important in augmented reality. Because it places digital objects into the view of the physical world, it’s possible to spot any errors or inconsistencies quickly. If it happens often, users can lose confidence in the solution.
Ironically, many users aren’t willing or able to pay for higher precision. But locating buried objects as well as producing the augmented views requires positioning accuracy beyond the capability of most BYOD solutions. As-constructed data is often collected by survey teams and may require more precision than the capability of handheld devices used by utility field technicians.
Augview CEO Mike Bundock says that the accuracy provided by software-defined GNSS can drive a significant increase in the use and performance of augmented reality. For many of his clients, the cost, size and weight of many external GNSS receivers outweighs the benefits of more accurate positioning. “Companies paying $800 for a tablet are not likely to spend $10,000 or more for a precise GNSS solution,” he says. “They have been waiting for an improvement in augmented reality, and a big part of it is driven by the economics and ergonomics of the positioning.”
Bundock looks forward to further evolution of the technologies that support augmented reality. He believes wearable solutions such as geospatially accurate augmented reality glasses can become a widespread part of daily life. “They will be your phone, map and view into the Internet,” he says. “There will be billions of these things.”
Do the Numbers Work?
In some ways, the software-defined GNSS approach seems to be an enigma. For years, GNSS hardware has been a major source of revenue for manufacturers in the geospatial industry. Trimble has placed a strong focus on software and cloud-based services.
Korec’s Beckerson believes that the added opportunities from the software-defined receivers will produce a net increase in income. “Engineers and surveyors need high-performance systems and will continue to use specialized GNSS solutions,” he says. “On the GIS side, less-precise applications have the potential to become high-volume business, especially if the initial cost of entry is low.” Beckerson is convinced that the new business can more than compensate for any erosion in hardware sales. He describes an example where a company or government agency may have hundreds of field users that want better precision, but the organization can’t invest in dedicated GNSS solutions. These companies can leverage the subscription approach for the higher precision. “Clients appreciate that they can pay for higher precision only when it’s needed,” Beckerson says. “At other times they are happy to operate at meter-level or less.”
Mike Bundock agrees. He explaines that Augview uses a subscription approach with its own software products as well. He says larger organizations often purchase solutions as long-term, capital expenditures. But smaller organizations and many subcontractors prefer to associate costs to specific projects and can let subscriptions lapse during slow periods. The low cost of entry and flexible cash flows will drive what he sees as an enormous new market.
As with many of the technologies surveyors and geospatial professionals use in the normal course of their day, software-defined GNSS receivers may be breaking new ground in bringing more capability to more jobs using tools that are already in their pockets.