Business Outlook: Critical GNSS: Safety, Financial, and Legal

Figure 1. Global CDMA subscribers. CDMA cellular infrastructure uses GPS for synchronization and optimal performance. Location-based billing will require GNSS integrity.

By Vidal Ashkenazi

The use of satellite navigation in civil aviation and other safety-critical navigation applications drove the development of satellite-based augmentation systems and differential networks to track and augment GPS, providing the prerequisite levels of accuracy, integrity, coverage, and availability. Deployment and operation of Galileo — independent, compatible, and interoperable with GPS — will significantly add to the levels of accuracy, coverage, and system integrity.
Meanwhile, safety-critical transportation is no longer the only critical application considered for satellite navigation and positioning. New and developing financial-critical, business-critical, security-critical, legal-critical and government- policy-critical applications demand levels of coverage, integrity, and availability matching those of safety-critical transportation.

Consider road user charging (RUC) proposed by the British government to replace the current fixed annual road tax, which only depends on a vehicle’s size and pollution rating. RUC is based on taxing a car owner who drives only on country roads less than another driver who uses city centers and motorways, often during rush hours, contributing to traffic jams and pollution. It would be fairer if road taxing were based on when, where, and how you drive. The same principles also apply to car insurance and city-center congestion charging.

So far, all seems straightforward. But consider that with direct telematic links to individual bank accounts, these charges could be debited automatically, or invoiced and debited like monthly utility bills. Once money is involved, the operation becomes financially-critical. There is a need to demonstrate that such charges not only have high accuracy and integrity, but that they are “correct, beyond all reasonable doubt”.

As a scientist and an engineer, I have always used the terms “statistical levels of accuracy and integrity.” This is the first time in my scientific life that I have to use that statistically meaningless, unspeakable term “correct”, which implies 100 percent of certainty. GNSS, this is your challenge!

The same is true of the timing of stock exchange transactions and location-based billing via mobile phones. As the levels of accuracy, coverage and integrity of GNSS improve, so will the credibility of satellite positioning as a highly accurate, reliable tool for economically-critical applications.

It is difficult to distinguish between security-critical and legal-critical navigation and positioning applications. Both types will require very high levels of accuracy, coverage, and integrity, but most applications that start as security-critical may end up in a court of law and become legal-critical. Examples include tracking precious or hazardous cargos, tracking suspected individuals or criminals released on parole, the location of suspect mobile phone calls, and the positioning of fishing vessels inside territorial waters.

Lastly, many government/policy-critical navigation applications connected with police, fire and ambulance services, national security, and emergencies will require secure/encrypted GNSS signals. In the United States, where GPS is directed by the PNT Executive Committee, co-chaired by the DoD and the DoT, this should not present a problem, because the system is considered a fully dual military-civilian navigation tool. This is not the case in Europe, which has yet to define the framework for governance and use of the Public Regulated Service within EU member states, and the status of non-EU states proposing to collaborate on Galileo.

VIDAL ASHKENAZI is CEO of Nottingham Scientific Ltd., a UK-based company involved in Galileo since its earliest phase. He is a charter member of GPS World’s Editorial Advisory Board since 1990. This article is excerpted from his keynote address at IAIN World Congress 2006 held in Korea.