Archives

GPS Constellation Management: Playing Not to Lose

October 22, 2009 - By

In sports, there is a phenomenon that sometimes occurs when a team is leading towards the end of a game. It’s called “playing not to lose.” The reason you are seeing high HDOP warnings from the NAVCEN and GPS “brownouts” during the day when RTK (GPS-only) isn’t working is because the GPS satellite constellation is sub-optimal. The current design of the GPS constellation is not focused on “playing to win”, but rather “playing not to lose.” read more

This article is tagged with and posted in Newsletter Editorials, Opinions, Survey, Survey Scene

“What Can GLONASS, GPS L2C, and GPS L5 Do for You?” Webinar Q&A Follow-up

October 6, 2009 - By

As I’ve been accustomed to doing, this newsletter addresses the questions you submitted during the Sept. 15 webinar entitled “What Can GLONASS, GPS L2C, and GPS L5 Do for You?”. There were some great questions during the webinar, and a lot of them. There were so many, in fact, that I’m going to break them up into a couple of different newsletter issues. Also, I need to update you on my trip to ION GNSS a couple of weeks ago. I might mix up the next newsletter with more Q&A as well as the ION GNSS update. read more

This article is tagged with and posted in Newsletter Editorials, Opinions, Survey, Survey Scene

Innovation: It’s Not All Bad

October 1, 2009 - By

Understanding and Using GNSS Multipath
Telltale signs of multipath are the fluctuations in the signal-to-noise ratios (SNRs) reported by some GNSS receivers. In this month’s column, the authors look at how an analysis of SNR values can be used to map the multipath environment surrounding an antenna so that models of multipath can be constructed to further minimize its effect. Also, although an annoyance for most GNSS users, it turns out that multipath has its positive points. read more

This article is tagged with and posted in Algorithms & Methods, Innovation

The System: Glitches and Vulnerabilities

October 1, 2009 - By

A range of unrelated events in September show that GPS, the world’s preeminent GNSS, remains a work in progress. The first in a series of deviations from normal GPS signal broadcasts during September was noted by researches at the University of New Brunswick, among others around the globe, who found that normal signals from the L1 and L2 transmitters on... read more

Expert Advice: GPS Forensics, Crime, and Jamming

October 1, 2009 - By

The most widely used of all GPS devices are in-car navigators. When vehicles carrying navigators are used for criminal purposes, records contained in the devices may be examined. Such investigations rely on newly developed forensic techniques that employ a combination of computer expertise and navigation knowledge, yielding valuable data for crime investigators. read more

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