Introduction

On May 1, 2000, the White House Office of Science and Technology Policy issued a short press release on behalf of President Bill Clinton which began:

Today, I am pleased to announce that the United States will stop the intentional degradation of the Global Positioning System (GPS) signals available to the public beginning at midnight tonight. We call this degradation feature Selective Availability (SA). This will mean that civilian users of GPS will be able to pinpoint locations up to ten times more accurately than they do now.¹

With the push of a button, the accuracy of civilian GPS receivers improved from roughly 50 meters to about 5 meters, creating a new and open market for location services—like the now ubiquitous turn-by-turn navigation—that had previously been impossible.² In June 2000, Steven W. Berglund, the president and CEO of Trimble Navigation, called the decision to turn off SA “a milestone in GPS history” that “underscores the importance of the technology as a global information utility.”³

He was right. Today, daily use of global navigation satellite system (GNSS) location services is taken for granted by everyone with a smartphone. In 2013, the direct economic impact of GPS in the U.S. alone was estimated to be between $37 billion and $74 billion.⁴ The 2017 EU GNSS Market Report predicts that the number of GNSS devices in use will “increase from 5.8 billion…in 2017 to almost 8 billion in 2020 – averaging an estimate of more than one device per person on the planet.” They predict further that the “global GNSS downstream market, which comprises both devices (e.g. GNSS receivers) and augmentation services,” will grow to €195 billion in 2025.⁵

Now, as investment in the GNSS market continues to increase, we are approaching another milestone that may prove as significant as the end of Selective Availability. That milestone is the emergence of new satellite navigation signals and signal processing capabilities that will, in a few short years, improve the location accuracy of consumer devices—including smartphones—from meters to centimeters.⁶ Just as happened with the ending of Selective Availability, this new level of accuracy will enable new applications, from autonomous vehicle navigation to augmented reality. Access to centimeter-level accuracy also opens up another use case, one that is not commercial but could have a far greater economic impact than any other: community land mapping. Community land mapping combines surveying with the collection of information about land ownership and/or occupancy to support the formal recognition of property rights.

In this report, we first discuss the developments that are making high-accuracy location services available to all for the first time. Then, through the lens of a recent case study, we look at the current state of community land mapping and how some of the remaining challenges can be addressed with new tools. Finally, we look at how new identity and trusted data systems can help enhance the non-geospatial half of community mapping, the collection of attribute data.

Note: In the appendices we include some lightly edited earlier writing on these subjects. In addition to providing greater detail on the evolution of GNSS and mobile mapping, these articles introduce and explain in simple terms the technical concepts referenced in the first section of this paper. Readers who are not already familiar with GNSS technology will find it helpful to read the appendices first. We also include a glossary of key technical terms and concepts.