More, More, More. Accuracy, Accuracy, Accuracy.

September 2, 2015  - By

Reliable, consistent positioning accuracy has always driven new product development in the survey and mapping sector of the GPS/GNSS market. It’s remarkable how quickly the provided accuracy in successive new survey products over the years has increased the required accuracy from users and customers in the field, and consequently the desired accuracy in a feedback loop to the product developers.

In other words, the degree of required accuracy has risen steadily over the three and a half decades since GPS was born. “Accuracy is addictive.” Somebody said that in the second decade of GPS development, that is, sometime in the 1990s. This statement continues to hold true, as true for this industry as Moore’s Law does for computer technology as a whole.

Moore’s Law states that overall processing power for computers will double every two years; as a corollary or an extension, the size of said computers gets cut in half every two years, and the cost (sometimes) also comes down by 50 percent. Moore’s Law in action in the GPS/GNSS industry has driven the product developments that we have consistently seen for many years.

We have seen the gradual tightening of accuracy requirements across all sectors of the positioning, navigation and timing (PNT) community with each passing year and with each new State of the Industry Report. This is the first time we have seen it cross the 1-centimeter line. Not in capability; sub-centimeter capability has been available for some time. But now that level of performance is the minimum acceptable “good enough” for more respondents in the survey and high-precision sector than any lesser degree of accuracy; in fact, greater than all other ranges combined.

To put this into measurable, statistical form, GPS World has just released its fourth annual “State of the GNSS Industry Report.” In the years that we have conducted the survey, the accuracy required for the majority of survey applications has steadily come down. No surprises here.

In 2013, those who said that the majority of this market sector needed accuracy of better than a centimeter amounted to only 8 percent of total respondents.

In 2014, this group rose dramatically to 35 percent, while close to a majority, or 47 percent, held that a range of 1 to 5 centimeters was “good enough.”

Now, in this year of 2015, the majority has shifted clearly to the side of 1 centimeter or better as the new standard of required precision; 51.25 percent held this view. From 8 percent to more than half in just two years — that’s some change!

How accurate is good enough for the majority of this sector?

How accurate is good enough for the majority of this sector?

Fewer people believe that a survey done completely on a computer and driven by remote-sensor data will occur in less than five years. Counter to last year’s expectations, most now think it will take longer than five years to come about.

How soon will a survey be performed entirely from a computer, using high-resolution satellite and/or UAV-collected data, without any instrumented field work?

How soon will a survey be performed entirely from a computer, using high-resolution satellite and/or UAV-collected data, without any instrumented field work?

Those who are addicted to 1-centimeter accuracy form the new majority. Their preferences and their behaviors will rule the positioning world, not just in survey, but across all sectors supplied by GNSS and increasingly by a broad range of PNT technologies: defense, transportation, UAVs, machine control, precision agriculture, and much more. These other sectors will presumably answer likewise — “1 centimeter accuracy, that’s what I need!” in coming years, following the trail blazed by the you high-precision surveying pioneers.

We have crossed the Rubicon. Unlike other obsessive behaviors, there is no going back in our case. This path is a one-way road to to the promised land of always-on, always-true, near-perfect provision of positioning.

How much effort are you devoting to mitigation of GNSS jamming or spoofing?

How much effort are you devoting to mitigation of GNSS jamming or spoofing?

About the Author:

Alan Cameron is editor-in-chief and publisher of GPS World magazine, where he has worked since 2000. He also writes the monthly GNSS Design & Test e-Newsletter and the Wide Awake blog.

1 Comment on "More, More, More. Accuracy, Accuracy, Accuracy."

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  1. Craig Roberts says:

    Thanks Alan. Very interesting observations although I wonder if clients really understand what they mean by a centimetre. This is a centimetre derived from a positioning system 20,000km out in space on 1.5 tonne satellites the size of combi vans moving at 4.5 km/s. Even after 13 days we can only derive orbits to 1-2cm, not to mention atmosphere errors, multipath, APCV at the SV and Rx antenna, measurement noise, inter-channel bias, combining GNSS constellations, optical plummets, bubbles, poles etc etc. Then there is earth tides and atmos loading for PPP, Earth fixed vs plate fixed coordinate systems and all the attendant transformation issues, ground deformation etc. We use numerous tricks to overcome all these problems but I wonder if clients desire 1 cm precision or accuracy or if 1 cm is unwittingly a code word for a few cm. And of course this is not to mention a legal cm and an authoritative cadastral survey where clients are prepared to risk millions of dollars on a mortgage based on the cm that the professional surveyor can measure. Regulations are challenged by these claims. This is the role of the professional surveyor to educate their clients (cadastral/ engineering/mining/hydrographic/everything) and diagnose their real concerns. Thanks again for a thought provoking article.