Archives

Innovation: Realistic Randomization

March 1, 2011 - By

New Way to Test GNSS Receivers
In this month’s article, we look at an approach to GNSS receiver testing that uses realistic randomization of signal amplitudes based on histograms of carrier-to-noise-density ratios observed in real-world environments. It can be applied to any simulator scenario, independent of scenario details (position, date, time, motion trajectory, and so on), making it possible to control relevant parameters such as the number of satellites in view and the resulting dilution of precision independent of signal-strength distribution. The method is amenable to standardization and could help the industry to improve the testing methodology for positioning devices — to one that is more meaningfully related to real-world performance and user experience. read more

This article is tagged with , , and posted in GNSS, Innovation, Signal Processing

Road Talk: Interoperability Considerations for V2X GNSS Receivers

March 1, 2011 - By

The presence of different types of devices, spanning multiple GNSS receiver types, configurations, hardware, software, and consequent widely varying capabilites, among a user mix of vehicles, cyclists, and pedestrians, poses several engineering challenges for a V2X scheme in which all road users share data with each other and with the road infrastructure. read more

This article is tagged with , , and posted in Road

Demands of the Road

March 1, 2011 - By

For use in billing drivers in road-user charging schemes, onboard units employing GNSS must meet stringent reliability and availability requirements, and at the same time, be based on low-cost equipment systems. The SIGNATURE unit includes an assistance service which provides ephemeris data and corrections from EDAS, optimized for user location. read more

This article is tagged with , , and posted in Road

The System: Test Data Predicts Disastrous GPS Jamming by FCC-Authorized Broadcaster

March 1, 2011 - By

Representatives of the GPS industry presented to members of the Federal Communications Commission (FCC) laboratory evidence of interference with the GPS signal by a proposed new broadcaster on January 19 of this year. The meeting and subsequent filing did not dissuade FCC International Bureau Chief Mindel De La Torre from authorizing Lightquared to proceed with ancillary terrestrial component operations, installing... read more

This article is tagged with , and posted in Galileo, GNSS, GPS Modernization, The System

Out in Front: Act Now to Protect GPS Signal

March 1, 2011 - By

GPS has become a key component of the U.S. national infrastructure, the driver of a significant part of the civilian economies of the world, and the enabler of millions of professional precision uses and consumer benefits. The viability of the GPS signal is now threatened — ironically by what appears to be a misguided attempt to increase accessibility to broadband by creating a needless zero-sum result for customers who want both services. The threat is real and immediate. read more

This article is tagged with and posted in From the Editor

Expert Advice: Positioning Protocol for Next-Gen Cell Phones

March 1, 2011 - By

As cell phones move into the next generation called Long-Term Evolution (LTE), also sometimes called 4G, and the methods of wireless transmission change, so too must the methods of providing location information over those new wireless interfaces. LTE Positioning Protocol (LPP) and Secure User Plane Location (SUPL) 2.0 and 3.0 are the key players in this new picture. read more

This article is tagged with and posted in Expert Advice & Leadership Talks, GNSS, Opinions

Iraq on the Map: Installing Reference Stations for Accurate Engineering

March 1, 2011 - By

As a geodetic surveyor, I served in the U.S Army for 10 years. During that time, my team and I developed a nationwide GPS infrastructure system called the Iraqi Geospatial Reference System (IGRS). We installed Continuously Operating Reference Stations (CORS) and High Accuracy Reference Network Stations (HARNS), the first Iraqi owned and maintained system of its type. read more

This article is tagged with , and posted in Construction, Defense, Mapping, Survey, Surveying, Uncategorized