GNSS (all systems) Archives - Page 152 of 164 - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design

January 9, 2011

Differences between Signal Acquisition and Tracking

Q: Why is acquisition of GNSS signals generally more difficult than tracking and what are the limiting factors?

A: A fairly good analogy of the difference between GNSS signal acquisition and tracking can be found in the rescue of victims of a sunken ship whose location is not accurately known. The first stage of the rescue attempt typically involves an aircraft flying a search pattern, which hopefully encompasses the location where the ship went down.

By Inside GNSS

Wavelets and Notch Filtering

For the complete story, including figures, graphs, and images, please download the PDF of the article, above.

The use of GNSS for safety critical applications is gaining interest, particularly amongst aviation users, who probably have the most demanding requirements. The GNSS frequency band containing the Galileo E5 and GPS L5 signals is designated as an aeronautical radio navigation service (ARNS) band, which enjoys legal protection from other services not allocated to this frequency on a primary basis.

By Inside GNSS

A Model-Based Approach

For the complete story, including figures, graphs, and images, please download the PDF of the article, above.

Galileo receiver designers require formal interface specifications for the Galileo signal-in-space (SIS) in order to write unambiguous and accurate specifications for Galileo receivers. To compute their positions, Galileo receivers must be able to retrieve timing and orbital information from the data stream conveyed in Galileo analog signals.

By Inside GNSS

Indian Regional Navigation Satellite System

For the complete story, including figures, graphs, and images, please download the PDF of the article, above.

In satellite navigation, a GNSS receiver must account for several sources of error such as relativistic effects, atmospheric propagation delay, offset of satellite clocks from system time and satellite ephemeris. In order to accurately compute user position, velocity, and time (PVT), these errors need to be predicted/estimated precisely.

By Inside GNSS

GNSS Interference, Detection and Mitigation

Britain’s Position, Navigation and Timing Network of the Digital Systems
KTN (Knowledge Transfer Network) presents a one-day workshop on
"GNSS Interference, Detection and Mitigation."

Professor Martyn Thomas will present the
conclusions of the Royal Academy of Engineering report on GNSS vulnerability, which was released on March 8.

The workshop will take place at Bushy House, National Physical Laboratory, Teddington, Middlesex on Thursday, March 10 2011 from 10 a.m. to 4 p.m.

Topics include:

By Inside GNSS

January 8, 2011

Natural Threats to GNSS Positioning

Britain’s Position, Navigation and Timing Network of the Digital Systems KTN (Knowledge Transfer Network) presents a one-day workshop on "Natural Threats to GNSS Positioning."

It will take place at Bushy House, National Physical Laboratory, Teddington, Middlesex on Wednesday, January 19 2011 from 10:00 a.m. to 3:30 p.m.

A number of natural phenomenon affect GNSS reliability and accuracy. These include:

By Inside GNSS

2011 West Coast Seminars: NavTech GPS

NavTech GPS will offer its 2011 west coast GNSS technical seminars at the Doubletree Hotel in San Diego, California from Monday, March 28 through Friday, April 1.

Over 25 years, NavTech GPS has provided GPS/GNSS applications solutions for military and research customers, with product choices from more than 30 manufacturers, and has organized basic and advanced GNSS seminars for engineers and technical professionals all over the United States.

The San Diego seminars include:

By Inside GNSS

December 31, 2010

GNSS Vulnerability — Jamming, Interference, Spoofing

Return to "GNSS Year in Review"

This subject gave the GNSS world a wake-up call on January 20 when the top gun at the U.S. Air Force told a conference audience that GPS is vulnerable to threats such as jamming and anti-satellite weapons and that the United States should reduce its dependence on the system.

By Inside GNSS

GNSS Interoperability, or Can’t We All Just Get Along Together?

Return to "GNSS Year in Review"

At first glance, interoperability and its implication of at least some degree of cooperation seem at odds with the idea of competing GNSS systems.

Yet the mantra of compatibility, interoperability, and even — in the terminology of GPS pioneer Brad Parkinson —interchangeability has taken on a nearly unanimous harmony in the pronouncements and deliberations of GNSS leaders.

By Inside GNSS

GNSS Year in Review: Three Trends That Matter

Yes, it’s that time — when we try to anticipate what 2011 holds for GNSS by analyzing (or just trying to remember) the highlights of the past 12 months in our global navigation satellite system industry.

First, 2010 was a busy year. Successful launches of 13 new satellites brought the number of GNSS spacecraft in orbit to more than 60. The highest level yet for both numbers launched and in the collective GNSS constellation.

By Inside GNSS

Handicapping the GNSS Horse Race

Return to "GNSS Year in Review"

We’ve come a long ways from the attitudes of the Cold War environment in which the Global Positioning System and GLONASS programs arose.

But that doesn’t mean that GNSS competition is a thing of the past. Indeed, the second most-read item on the Inside GNSS website during this year was a March 2009 article entired “GPS, GLONASS, Galileo, Compass: What GNSS Race? What Competition?”

By Inside GNSS

Insidegnss.com’s Greatest Hits: Loran’s end, GNSS horserace and magazine articles online

What do you read? In 2010, there were 37 percent more visits to insidegnss.com, and it’s interesting to see who among the GNSS interest groups dropped by and which topics attracted the most attention.

By Inside GNSS

December 15, 2010

ION GNSS 2011: 24th Institute of Navigation GNSS Conference

ION GNSS 2011 will take place at the Oregon Convention Center in Portland, Oregon from September 20-23. Tutorials will be held on September 19 and 20.

This will be the 24th international technical meeting of the Satellite Division of the Institute of Navigation. It is the world’s largest and oldest GNSS conference,
founded in 1987 as the ION GPS conference.

The headquarters hotel is Portland’s downtown Hilton and Executive Tower.

By Inside GNSS

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Differences between Signal Acquisition and Tracking

Wavelets and Notch Filtering

A Model-Based Approach

Indian Regional Navigation Satellite System

GNSS Interference, Detection and Mitigation

Natural Threats to GNSS Positioning

2011 West Coast Seminars: NavTech GPS

GNSS Vulnerability — Jamming, Interference, Spoofing

GNSS Interoperability, or Can’t We All Just Get Along Together?

GNSS Year in Review: Three Trends That Matter

Handicapping the GNSS Horse Race

Insidegnss.com’s Greatest Hits: Loran’s end, GNSS horserace and magazine articles online

ION GNSS 2011: 24th Institute of Navigation GNSS Conference