201609 September/October 2016

September 8, 2016

Single Versus Multiple

Dr. Kyle O’Keefe, University of Calgary

In the beginning, there was just one GNSS — the Global Positioning System — and just one fully available signal on the L1 frequency.

Eventually, some clever scientists discovered how to exploit certain characteristics of the encrypted L2 signal to come up with so-called codeless and semi-codeless techniques that enabled dual-frequency positioning. This hastened the development of user equipment that used the carrier phase of signals as well as the code to deliver high-precision results.

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By Inside GNSS
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Mikel Miller’s Compass Points

Mikel Miller’s favorite equation

Return to main article: "Mikel Miller: Science, Service, and Family"

COMPASS POINTS

GNSS event that most signified to you that GNSS had ‘arrived’

Testing of the initial handheld units from vendors such as Trimble’s two-channel GPS receiver and Rockwell Collins’ PLGR. “We thought, ‘What an amazing capability to have a handheld device that all you had to do was turn it on and it told you where you were – wow!’”

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By Inside GNSS
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The Particular Importance of Galileo E6C

Equations

The Galileo E6 signal is centered at 1278.75 MHz, and comprises three signals: an authorized signal (E6A, the publicly regulated service, PRS plus two civilian signals), a data component (E6B), and a pilot component (E6C). Both E6B and C are modulated using binary-phase shift keying (BPSK) code division multiple access (CDMA) memory codes, having lengths of 5,115 chips and chipping rates of 5.115 Mcps.

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By Inside GNSS

It’s Time for 3D Mapping–Aided GNSS

Figures 1-6

Real-time position accuracy, achievable in dense urban areas using low-cost equipment, is currently limited to tens of meters. If this could be improved to five meters or better, a host of potential applications would benefit. These include situation awareness of emergency, security and military personnel and vehicles; emergency caller location, mobile mapping, tracking vulnerable people and valuable assets, intelligent mobility, location-based services and charging, augmented reality; and enforcement of curfews, restraining orders and other court orders.

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By Inside GNSS

Geolocation Privacy

Reasonable Expectations of Privacy and a discussion of privacy in the United States typically begins with the Fourth Amendment of the U.S. Constitution, which provides that “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.” In U.S. v Katz, the U.S. Supreme Court found that this Fourth Amendment protection created an individual’s constitutional right to privacy.

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By Ingo Baumann
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