Category: GNSS

Editor’s Note: Alan Cameron is editor-in-chief and publisher of GPS World magazine. He also writes the monthly GNSS Design & Test newsletter. The views expressed are his own.

“It’s tough to make predictions, especially about the future.” This insight comes from the 20th-century American sage Yogi Berra. Yet predictions — hedged guesses, if you will — form the basis of nearly all new business ventures and decisions in ongoing business activities.

For surveyors in the year 2015, one of the key predictions — or guesses — to make concerns the next GNSS to come predictably and reliably online, to augment GPS where GPS alone does not fully function: under canopy, in dense urban environments, and so on. More satellites visible at more varied angles in the sky can help surmount these obstructions.

Staking the future of one’s business, in the form of new equipment acquisition, in such an environment is a bit like betting on a long-distance horse race. First one steed surges to the head of the pack, then it falls back as another charges forward. We have seen this pattern repeatedly in the growth of GLONASS, Galileo and BeiDou.

Some may say that GLONASS, the Russian system, has already won the race (the first heat, at least) and currently fills the role of GPS partner in precision surveying. It does, to some extent, but its future viability is cloudy — and its past record is patchy, to say the least. It rose to full operational capability around the turn of the century, then fell very, very low in numbers as short-lived satellites expired and were not replaced at sufficient rate. Recently, GLONASS has mounted a resurgence, but that has been marred by repeated launch failures and a disturbing anomaly. It cannot be counted or confirmed a winner, yet.

I spoke yesterday with an expert and veteran professional land surveyor who expressed the opinion that the manner in which surveying is conducted will change more in the next five years than it has in the last 25. Keep in mind that the last 25 years saw enormous changes themselves, as GPS significantly transformed, upgraded and made vastly more efficient most surveying activities.

Betting on a horse race in such a rapidly changing environment becomes even more chancy.

Here’s a tip from a racetrack tout: don’t count Galileo out.

GLONASS we recounted briefly above. BeiDou recently achieved a regional operations status over Eastern Asia, but further developments there have been puzzlingly quiet for some time.

The European system has come on with agonizing slowness since the year 2000, suffering many delays and most recently what could have been a debilitating failed dual launch. But the combined strength of the European Union continues to push determinedly forward, and the program has an ambitious schedule with an eye firmly fixed on operability. And some recent research results tend — perhaps — to substantiate the claim, long pooh-poohed by those in the United States, at least, that Galileo will eventually prove “better” than GPS. Details further on.

What might a prudent yet pragmatic, forward-looking surveying firm do in this uncertain environment, where the only certainty is change, and likely to be rapid change at that? Here’s another racetrack tip: don’t make any big bets just yet, but study the field closely and continuously. In particular, watch Galileo’s performance.

A further item to be checked in Galileo’s favor: its system operators have long been in close talks with the U.S. government on many matters involving co-operation and interoperability. As recounted in a recent story concerning the Federal Communications Commission’s surprising role in this matter, the Europeans are filling out the proper forms for full accreditation within the United States. This could turn out to be important in business operations.

Back to studying the field closely: also study leading manufacturers’ offerings in this regard. They also are making bets on the future; quite possibly they have better information, and/or have done more extensive analysis of what information is available, paired with in-depth, highly technical research and development of signal characteristics and how signals from disparate GNSS can be most productively combined.

A quick scan of GPS World’s 2015 GNSS Receiver Survey shows the following key manufacturers (among others) have GPS receivers now commercially available that are Galileo-ready: Altus Positioning Systems, Ashtech, Geneq, iFEN, JAVAD GNSS, Leica Geosystems, NovAtel, NVS Technologies, Septentrio, Sprecta Precision, Spectrum, Topcon, and Trimble.

Better than GPS???

Supporters of Galileo have long raised hackles west of the Atlantic with claims that Galileo would provide better accuracy than GPS. Not! cried the faithful, and especially not when the modernized and improved, strengthened, more accurate GPS III signals are coming along just as fast if not faster than Galileo. Recently the pace of GPS III has come into question; can the Gold Standard and clear leader for 25+ years really be falling back into the pack?

Let’s disregard that question for the time being, and look at some recent research, to be reported in full in the cover story of GPS World magazine’s April issue, out soon. In it, the authors (two German and one American researcher) report:

“Analysis of new Galileo signals at an experimental ground-based augmentation system (GBAS) compares noise and multipath in their performance to GPS L1 and L5. Raw noise and multipath level of the Galileo signals is shown to be smaller than those of GPS. Even after smoothing, Galileo signals perform somewhat better than GPS and are less sensitive to the smoothing time constant.”

This is all pretty arcane and a bit removed from current field of operations, as far as surveyors are concerned. But it does signal something, and it provides food for thought.

The researchers obtained their results using four JAVAD Delta receivers, all connected to Leica AR 25 choke ring antennas.