Archives

Out in Front: The Daughter of Time

July 1, 2011 - By

"Truth,” wrote Sir Francis Bacon, “is the daughter of time.” He meant that any account, repeated often enough by different people in different places, at different junctures, eventually becomes accepted as historical fact, or truth, by those with no direct knowledge of the matter. That’s why it is so important to repudiate and expose lies at every encounter. Never, ever let one pass. Even when it’s the same one that you dispelled yesterday — or thought you had taken care of. One thing about liars, they keep coming back. They don’t give up. Would you give up, if you had $20 billion at stake? read more

This article is tagged with , , and posted in From the Magazine, Opinions

Innovation: Multipath Minimization Method

July 1, 2011 - By

Mitigation Through Adaptive Filtering for Machine Automation Applications
Multipath is real and omnipresent, a detriment when GPS is used for positioning, navigation, and timing. The authors look at a technique to reduce multipath by using a pair of antennas on a moving vehicle together with a sophisticated mathematical model. This reduces the level of multipath on carrier-phase observations and thereby improves the accuracy of the vehicle’s position. read more

This article is tagged with , , and posted in From the Magazine, Innovation, OEM

The System: LightSquared Interference with GPS

July 1, 2011 - By

And the Beat Goes on Developments in the LightSquared saga came fast and furious in June; highlights are listed below and briefly recapped in the adjacent news story. It will be dated by the time you receive this issue, as it went to press three weeks prior. For current events, see Top Story and Latest News, and the full versions... read more

This article is tagged with , and posted in GNSS, OEM, Survey, Transportation

Integrity for Non-Aviation Users: Moving Away from Specific Risk

July 1, 2011 - By

Non-aviation users of satellite- and ground-based augmentation systems do not require the conservative level of integrity built into these systems for aviation users. Removing it can produce substantial benefits in terms of smaller error bounds and improved availability. read more

This article is tagged with , , , , , and posted in Transportation

Lone Sentinel: Single-Receiver Sensitivity to RF Interference

July 1, 2011 - By

Using signal-to-noise measurements from a single commercial-grade L1 GPS receiver, it is possible to detect interference or jamming that is above the thermal noise floor and below a power that causes loss of position. read more

This article is tagged with , , and posted in OEM

On the Edge: Tracking Slips and Creeps: Earthquake Monitoring Gets Substantial Boost from GPS

July 1, 2011 - By

The Earth’s surface is constantly shifting, being deformed as earthquake faults accumulate strain, and slip or slowly creep over time. Not long ago, scientists relied solely on seismometers to monitor the earth’s movements. Today, GPS has taken prominence as an indispensible tool. PANGA, the monitoring network covering the Pacific Northwest, uses GPS to monitor this movement by measuring the precise position (within 5 millimeters or less) of stations near active faults relative to each other. By determining how the stations have moved, ground deformation can be determined. read more

This article is tagged with , , , , , , , and posted in Survey

Letters to the Editor: LightSquared Satellite Case Skimpy

July 1, 2011 - By

Thank you for the story “LightSquared, FCC Rebuttals Distort Record” (see www.gpsworld.com/distort). One thing worth clarifying: you state, “It appears that the purpose of Lightsquared’s satellite service is, now, to provide ancillary service in remote areas not covered by the ubiquitous primary terrestrial network, or in the event that the terrestrial network is destroyed — exactly the opposite of what the FCC authorized and the GPS industry had understood and agreed to.” read more

This article is tagged with , , and posted in From the Magazine, Opinions

Expert Advice: Critical Offshore Applications of SBAS GNSS

July 1, 2011 - By

Precise positioning of many different kinds of vessels and other equipment depend upon satellite-based augmentation systems (SBAS) of GNSS, principally GPS and GLONASS at this time. The applications range from exploration to production and delivery of hydrocarbons to shore-based installations and navigation of very large crude carriers, or oil tankers. Decisions and recommendations are strongly needed to keep these services free from interference. read more

This article is tagged with , , and posted in From the Magazine, Opinions
« Previous Page
Next Page »