Archives

UrsaNav Testing Wide-Area Timing Alternative

March 5, 2012 - By

As a result of a Cooperative Research and Development Agreement (CRADA) between the U.S. Coast Guard and UrsaNav, Inc., on-air tests are being conducted from the former Loran Support Unit site in New Jersey. One of the CRADA’s goals is to research, evaluate, and document a wireless technical approach as an alternative to GPS for providing precise time. The ability... read more

F4Devices Announces Flint Rugged Handheld

March 1, 2012 - By

F4Devices, a subsidiary of F4 Tech and strategic partner with BAP Precisions, Taiwan, has introduced a new generation of high-precision GNSS devices for GIS field applications, the Flint rugged handheld. With the new Flint handheld, field workers requiring a rugged mobile handheld device have a unit that is lightweight, compact, rugged, and cost-effective, the company said. The Flint fits well into GIS field data collection markets such as municipalities, oil and gas and forestry, F4Devices said. read more

The System: NTIA, FCC Waiver No More on LS

March 1, 2012 - By

“We conclude that LightSquared’s proposed mobile broadband network will impact GPS services and that there is no practical way to mitigate the potential interference at this time.” These words from Lawrence Strickling, U.S. assistant secretary for communications and information and head of the National Telecommunications and Information Administration (NTIA), appear to signal the end of LightSquared’s run. Strickling’s letter to... read more

Galileo’s Surveying Potential: E5 Pseudorange Precision

March 1, 2012 - By

New Galileo signals have great potential for pseudorange-based surveying and mapping in both optimal open-sky conditions and suboptimal under-canopy environments. This article reviews the main features of Galileo’s E5 AltBOC and E1 CBOC signals, describes generation of realistic E5 and E1 pseudoranges with and without multipath sources, and presents anticipated horizontal positioning accuracy results, ranging from 4 centimeters (open-sky) to 14 centimeters (under-canopy) for E5/E1. read more

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The Business — March 2012

March 1, 2012 - By

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Sensing Location: Software Receiver Estimates Signal States During Outages

March 1, 2012 - By

Future safety-relevant driver assistant systems demand vehicle state estimations accurate enough to match the position within a road lane, which cannot be provided by standalone GPS. A promising approach to meet the requirements is the fusion of standalone or differential GNSS measurements with vehicle sensor data like odometers or accelerometers. To achieve deeper sensor integration, a software GNSS receiver was developed at the Institute of Flight Guidance (IFF) that is able to use dead reckoning sensors to support its signal acquisition. This article presents an approach to estimate the signal states during outages based on the tightly coupled vehicle state, which reduces the reacquisition time and significantly increases the signal availability. read more

Letters to the Editor: Antennas and the Human Body

March 1, 2012 - By

We have been reading with much interest the Innovation column, “GNSS Antennas and Humans” (Innovation, February issue). As the interaction with the human body is something many companies designing GPS into their products do not consider, it is great to see this topic being given some recent attention. We do feel, however, that we should comment on some issues we see in the article, especially as one of our antennas has been used as part of the testing. read more

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Unmanned Air Systems: Precision Navigation for Critical Operations

March 1, 2012 - By

An alternative precision GPS architecture, Precision RELNAV, enables an airborne tanker plane and a Navy unmanned combat aircraft to navigate independently to a high degree of precision without requiring carrier-cycle ambiguity resolution using precision GPS ephemeris updates to a tightly coupled GPS/inertial solution onboard each aircraft. The solution rivals that of conventional relative kinematic techniques while providing more robust positioning that reduces message traffic between aircraft and does not require a long filtering time. read more