Latest Articles


July 24, 2024
Q: Are RAIM and Advanced RAIM useful for applications that take advantage of differential GNSS corrections for integrity?

A: Receiver Autonomous Integrity Monitoring (RAIM) and Advanced RAIM (ARAIM; known more generally as Solution Separation RAIM, or SS-RAIM) were originally designed to…

By Sam Pullen


March 26, 2024
GNSS Spoofing and Jamming in Eastern Europe

Q: What do we know about recent observations of GNSS interference and spoofing in Eastern Europe? What lessons can we learn regarding civil…

By Sam Pullen


July 24, 2023
Q: How can GNSS augmentation services be combined to simultaneously support multiple user classes with demanding but varied requirements?

SAM PULLEN STANFORD UNIVERSITY, FRANCESCO RISPOLI, ALESSIA VENNARINI, ARIANNA PERSIA, RADIOLABS , ALESSANDRO NERI, ROMA TRE UNIVERSITY AND RADIOLABS, ROBERTO CAPUA SOGEI A: Many augmentations…

By Sam Pullen


March 7, 2022
Q: How could GNSS users determine in real time that their received navigation signals are correct? What methods are recommended, and when might they go into operation?

Cryptographic techniques can optimize the trade-off between authentication integrity (minimizing the probability of authenticating a modified message), ease of modification of existing signals…

By Sam Pullen


February 5, 2021
How can the parameters given in the most recent GPS Standard Positioning Service (SPS) Performance Standard (SPS PS) be used to quantify the performance of GPS applications?

The value of the GPS SPS PS goes far beyond the specific parameters that it contains. It has a great deal of information…

By Sam Pullen


October 5, 2020
Can Analytical Techniques Guarantee That GNSS Errors Are Bounded Under Rare Conditions? What Techniques Are Available?

Research has focused on methods to analytically determine bounding probability distributions and parameters and identify the conditions under which such bounds are guaranteed…

By Sam Pullen


January 26, 2020
What freeware or open-source software packages are available to support GNSS performance evaluations?

In the years since civil and commercial use of GPS and GNSS became common in the mid-1990s, a variety of software tools have…

By Sam Pullen


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