An ambitious pilot project, to deliver high precision measurement as a statewide amenity, is under way in Montana. Agriculture, transportation, construction, mining, commerce, public safety, and the sciences have benefited substantially from such initiatives, nationally and globally—will Montana take the next step?  

The World’s Measuring Tape

GPS is already a very beneficial technology, but what if it could be made even better and more precise? This is already possible, and Montana has an opportunity to enable high precision GPS statewide.

Satellite positioning, location, and measurement has brought over $1.5T in direct economic benefits to the U.S. private sector since 1984 (the beginning of widespread civilian use of GPS). This number, from a recent U.S. Department of Commerce Report  does not include compound benefits, nor those realized by global economies—extended totals could be four-fold. This from a system that was originally chartered for strictly defense purposes, and was built and is operated at a fraction of the realized benefits—one of the most successful public technology investments in history.

The same report puts location-based services (apps, delivery services, consumer devices, etc.) as having realized $215B in such benefits, energy at $46B, surveying and mapping at $48B, mining at $13B, electrical systems $15B, and precision agriculture at $6B. Telematics (efficiency gains, cost reductions, and environmental benefits through improved vehicle dispatch and navigation) comes in at a staggering $325B.

These benefits will continue to grow, especially with the current boom in development of assisted and autonomous vehicles, precision guided robotics for industry, and construction automation. An additional boost is coming in the form of high precision GPS—improving current uses and enabling even more. Whereas GPS, as most commonly applied, is only precise only in the range of 3 feet to 20 feet, high precision GPS applications can deliver precision of less than an inch.

High precision GPS does though require specialized equipment and some ground infrastructure. But even with these requirements, the benefits can outweigh the investments rapidly—in years, weeks, days, and for some applications in hours. An example is precision agriculture, implemented on the local level for many years. The positions of seeds can be marked to the inch, allowing precise application of water, fertilized, then weeding and harvesting. Depending on the type of crop, such precision guidance can bring a 5%-30% time gains for applicable tasks, and reductions in fuel and fertilizer. High precision GPS, as a ubiquitous utility could expand uses in agriculture and more. An example from public safety is road accident investigations; rapid measurements can reduce lane and road closure times.

About 20 years ago, a new way to bring high precision GPS to regions, states and entire countries was developed, capable of serving nearly unlimited numbers of end users. This solution, first developed in Europe, is called “real-time networks” (RTN).

RTN’s spread rapidly, serve as new type of utility. In the service area of an RTN, GPS augmentation is readily available to anyone who can access it via the internet, apply it to GPS devices (that support such applications).  Positions are then derived, precise to less than an inch, in real-time, and even in moving vehicles. Most developed (and many developing countries), and nearly every U.S. state have RTN. Montana is a little late but has initiated a pilot RTN.

Bricks Moons

To understand how RTN work, let’s take a look at the history and ongoing innovation behind this measurement magic. In 1869, American writer Edwin Everett Hale published his novella, “The Brick Moon” that is widely recognized as the first imagining of an artificial satellite—and one designed as an aid to navigation. GPS, more specifically the U.S. Navstar system, inaugurated in the 1970s, has delivered benefits to society and the economy far beyond its original military charter and far beyond what its founders imagined.

Not only is GPS the default positioning and navigation resource for everything from surveying to ride-share apps, but it also serves as the world’s clock; nanosecond synchronization makes the internet and cellular systems possible. The same Department of Commerce report estimates that the benefits of precision timing, in the form of improved reliability and bandwidth utilization for wireless and computing networks alone, is $685B.

GPS was not originally very precise: the first military charter was +/- 30 feet, available over 95% of the globe. The current “constellation” of 24+ satellites transmits multiple signals that public, private, and scientific R&D teams have further developed methods and tools for to hone GPS results down to high precision—sometimes in the order of millimeters. This is how a tractor can maintain repeatable row-to-row and year-to-year accuracy of less than an inch and how a surveyor doing a rural boundary survey can measure in minutes what might have previously taken days.

But even GPS (as a term) is “kind of” obsolete. There are now multiple arrays, or “constellations” of these global navigation satellite systems. GNSS is the new term for this array of a half a dozen constellations (some global and some regional) hosted by different countries. The U.S. GPS constellation is still the gold standard and the most widely used, but the extra constellations improve what was already amazing. In early days when there were few GPS satellites and while surveying, might have to have to plan ahead and work (often at night) waiting for a minimum number of satellites to be briefly in view. But now the number of satellites has quadrupled (and is growing); GNSS can work even in limited sky conditions, e.g. under moderate tree cover, and in urban canyons.

Real-time Networks

How does an RTN work? To wring the last few inches out of GPS/GNSS, the most common method is differential: setting up one high-precision GPS/GNSS receiver on a known point (i.e. “base”) and transmitting (usually by pairs of radios) augmentations or corrections to another, called a “rover.” Using two in this manner works well over short distances and is often done on a one-to-one basis. To deliver high precision across a whole city, country, state, region, or country, arrays of “base” stations are set up to create RTN “network corrections” and deliver them via the internet/cellular to an unlimited number of rovers.

The typical spacing of RTN base stations is between 50km-100km (depending on local conditions and needs for redundancy). These are established by governments, agricultural concerns, scientific bodies, and private for-profit networks. Japan has a single array of 1,200, Washington State 125, Germany around 300—there are over 500 such networks worldwide.. Some are funded fully by states (e.g. Ohio) and are used freely, others have been built by private firms charging subscriptions, and others are public/private cooperatives (e.g. Washington State) that earns nominal subscription income to cover operations from non-partners.

Iron, Brass, and Stones

Legacy measurement methods were labor intensive, and tasks that might have taken days or weeks can, for some applications, be done with and RTN rover in minutes. Legacy positioning infrastructure is arrays of surveying marks, monuments, benchmarks, etc.; physical references of latitude/longitude, elevations, and coordinates. Some were set yesterday, some were set hundreds of years ago using stone, metal, wood, even items that were handy, like wagon axles. Those marks continue to be valid and essential for such needs and were served well by legacy tools and methods. The legacy physical marks will continue to be there, as they often hold legal weight, but the tools we use to measure today—and much more—have changed.

Measurements using legacy analog surveying and mapping instruments like measurement chains, graduated tapes, the familiar transits you see on tripods, and spirit levels have traditionally been taken relative to those physical reference marks. We might be most familiar with relative type surveys performed, for instance, to determine where your property line is. Satellites and lasers have not usurped all analog measurement tools or methods for activities like residential properties surveys (though are widely used for even that) but have fundamentally changed the way we measure nearly everything else.

Making Use of the Big Sky

Montana is a little behind most U.S. states in developing modernized positioning infrastructure. This is not from lack of foresight, but rather it’s a function of a large land area with relatively sparse population and economic activity that would warrant early investment in such infrastructure. Those equations have changed with a boom in high-precision uses and less-expensive infrastructure.  

Costs are not negligible to build and run an RTN, but far more affordable than even a decade ago. Stations can still cost between $10K and $40K, there needs to be central operations (network servers and specialized RTN software), and someone to administer it. A statewide RTN in the past might have cost several million dollars to establish and six-figures to operate annually, but even then, costs were often shared among multiple stakeholders/partners. Montana would be getting into RTN at a time when the costs have been greatly reduced compared to what early adopters had to invest, and cost sharing cooperatives are now more common.

There have been multiple initiatives in Montana over the past 15 years to develop RTN in different parts of the state, and a few initiatives seeking statewide coverage.  About five years ago, several tribal nations began to work with the Montana Department of Transportation (MDT) to establish base stations in about 40 locations around the state, in tribal nation regions (e.g. Blackfeet and Fort Peck) and along transportation corridors. While these base stations can provide high-precision differential solutions in their respective immediate vicinity, the prospect of combining these with other existing base stations for network solutions sparked renewed interest in forming a statewide RTN.

Interstate Assistance and the MTSRN Pilot

In early 2018, Harry Barnes, Chairman of the Blackfeet Tribal Business Council, and Montana Governor Steve Bullock each sent letters to Washington Governor Jay Inslee asking for technical assistance in helping set up an RTN pilot for Montana. Washington state has had a public/private cooperative network since 2002 ,and has assisted several states in developing RTN.

The Montana State Reference Network (MTSRN) pilot was launched in February of 2018,  hosted as a temporary sub-network of the cooperative network in Washington State. It was formed by connecting data streams from the new MDT and tribal stations and others that had been previously built by cities, counties, agriculture equipment dealers, universities, and scientific entities (established for plate tectonics studies)—60 in total. While put together rapidly and only covers about half of the state, and remote operation is not optimal, the RTN pilot is otherwise fully functional.  It provides an opportunity for MDT, the tribal nations, other pilot partners, and potential stakeholders to test-drive a live RTN. It is great starting point from which to grow a Montana network. But the pilot is expected to wrap up by the end of 2020.

Several entities, including several state agencies, are exploring options to fund conversion of the pilot to a permanent RTN locally hosted and operated in Montana. Initial investments would not necessarily be as high as those for early RTN in other states, as so many stations have already been established in MT.  And if operated as a cooperative, it could likely grow rapidly and “organically” as has been the experience of other RTN.   For instance, the RTN in Washington, one of the first in the U.S., started as only four stations in the Seattle area in 2002 hosted by a local utility. Soon the surrounding cities, countries, state transportation regions, academic institutions, and private surveying/engineering firms began adding stations. Statewide coverage was achieved in 2009, and it operates as a self-sustaining cooperative.

Invisible Benefits

As RTN developed globally and became the default positioning infrastructure, many new end-user applications were developed. In addition to those end-uses previously mentioned, science and environmental concerns are key users of RTN, from plate tectonic studies to atmospheric research. Scientific and academic entities are also major partners/investors in RTN infrastructure. For example, a third of the RTN stations in the current pilot were established by scientific research groups. One example of the many emerging applications is determining snowpack through the observation of deflected GPS signals. And then there is autonomous vehicle research.

One of the misconceptions about vehicular autonomy is that it relies solely on GPS, and the fear is that an error in the GPS might be disastrous. No proposed or deployed autonomous vehicle system relies solely on any one technology. Typically, there are five or six technologies bundled together: inertial devices, accelerometers, cameras, scanners, etc. complementing the GPS/GNSS. Developers of systems for autonomous/assisted navigation have been augmenting with GPS/GNSS corrections from RTN. It may be many years before you can look forward to (or worry about) autonomous vehicles, but the development environment for autonomy is booming and represents an opportunity to help fund RTN.

Always Moving

Globally, another driver for RTN development is the modernization of reference frameworks (AKA “datum”). Headlines in 2016, like the following from the National Geographic, announced, “Australia Is Drifting So Fast GPS Can’t Keep Up.” There are elements of scientific truth to such headlines, but perhaps the real story is not very exciting. Digging deeper though reveals something that is quite relevant for the U.S. and Montana. 

In recent years, Australia and many other countries have chosen to update their geodetic frameworks (i.e. the basis for reference “datums” and coordinates due to tectonic plate drift)—but it is not due to GPS being unable to “keep up.” Rather, it was that geodetic (Earth measurement) tools have evolved to be so precise that the very nature of how we measure, position, and navigate has changed. We can see the size and shape of our dynamic Earth better than ever before. It is our reference frameworks that need to catch up, and our “positioning infrastructure.”

Just as other countries have done, the United States will be updating the National Spatial Reference System—the nation’s datum—in 2022. It will be based on decades of data from GPS stations across the country (and globe); more precise and reliable than ever before. RTN data, paired a new purely gravity-based elevation datum model, enables capable GNSS instruments to provide global positions, in real-time, precise to less than an inch, and for some applications to millimeters.

The science of “where” is everywhere, and high precision is the currency of such advances. While the underlying science and reasons for such changes may be a bit too esoteric to digest for those outside of related sciences and industries, the impacts of ubiquitous high-precision positioning touch nearly every aspect of our daily lives—behind the scenes. To eschew updating could result in becoming “worse for the where” in the long run.

Will Montana step up and plant the seeds for an RTN to grow statewide? The pilot has created a transferable foundation, and by the end of 2020 users will have had two years’ experience to build on. The Earth and the technologies used to measure it are constantly on the move, along with great opportunities, like a Montana network—one that should not be missed.