Global Navigation Satellite Systems Engineering, Policy, and Design
NovAtel OEM615 receiverNovAtel, Inc. has introduced the newest member of its OEM6 receiver family: the OEM615. Measuring only 46x71x11 millimeters (1.81×2.79×0.43 inches) and weighing 24 grams (0.84 ounces), the diminutive OEM615 provides precise positioning in a familiar, compact form factor.
By Inside GNSS
European Geostationary Navigation Overlay Service (EGNOS). ESA illustrationCiting European Space Agency (ESA) studies that showed “harmful interference” to Galileo receivers operating up to 1,000 kilometers from LightSquared base stations, a European Commission (EC) official has told the Federal Communications Commission (FCC) about his “deep concerns” about the wireless broadband company’s terrestrial transmissions in the 1525–1559 MHz band next to L1 GNSS frequencies.
By Inside GNSS
The gloves have come off now that test results show clearly the probable effects on GPS of LightSquared’s proposed wireless broadband network: widespread, debilitating interference to GPS receivers.
By Dee Ann Divis
Q: What is a virtual reference station and how does it work?
A: To reach centimeter-level — or even better — accuracy of positioning typically requires use of precise dual-frequency carrier phase observations. Furthermore, these observations are usually processed using a differential GNSS (DGNSS) algorithm, such as real time kinematic (RTK) or post-processing (PP). Regardless of the specific differential algorithm, however, implicit in the process is an assumption that the quality of the reference station data is consistent with the desired level of positioning accuracy.
By Inside GNSS
GPS III satellite. Lockheed Martin illustrationLockheed Martin has announced the successful, on-schedule completion of a system design review (SDR) for the second-phase of next-generation GPS satellite development, the IIIB increment.
The company’s Space Systems division in Newtown, Pennsylvania, is under contract to produce the first two of a planned eight GPS IIIA satellites, with first launch projected for 2014. The contract includes a Capability Insertion Program (CIP) designed to mature technologies and perform rigorous systems engineering for future GPS III increments.
By Inside GNSS
FIGURE 1: System architectureCooperative vehicle safety applications should preferably have two-meter horizontal accuracy and six-meter vertical accuracy, all with a 95-percent availability. The solution must be developed to incorporate lower-cost sensor options, specifically, lower-cost inertial measurement units that can be generally characterized by the gyro drift of 100 degrees per hour and an accelerometer bias force of twice its mass times gravity (two milligals).
By Inside GNSS
Anechoic chamber test site at U.S. Naval Air Systems Command (NAVAIR) facility in Patuxent River, MarylandInterference can pose a threat to the reception of GNSS signals in a variety of ways. Even low-level signals have the potential to interfere with GNSS receivers, which require very high sensitivity for acceptable performance due to the extremely low received GPS signal power at the Earth’s surface.
By Inside GNSS
The House Appropriations Committee approved its version of the Fiscal Year 2012 (FY12) Department of Defense Appropriations Act (H.R.2219) on June 14, cutting funds from the next-generation GPS space (GPS III) and operational control (OCX) segments, while adding money to the current GPS IIF satellite allocation.
By Inside GNSS
The report concerns economic effects on high precision commercial uses of GPS, such as precision agriculture. (U Calif. photo)Research released yesterday (June 22, 2011) indicates that interference from LightSquared cellular broadband transmitters could cost manufacturers and users of commercial GPS technology up to $96 billion in annual losses.
By Inside GNSS
LightSquared graphicWith test results and congressional sentiment running against it, LightSquared has received a two-week extension for filing its report and recommendations, due to the Federal Communications Commission (FCC) yesterday (June 15, 2011), on likely interference to the GPS L1 band.
Meanwhile, a congressional critic of LightSquared’s effort to roll out a 4G/LTE broadband cellular service adjacent to the GPS frequency has called on the agency to rescind its waiver of limits on the company’s plans to build a high-powered national network of terrestrial transmitters.
By Inside GNSS
Lockheed Martin Space Systems Company, which is developing the GPS IIIA generation of satellites,
announced today (June 14, 2011) a 7.5 percent reduction in its
workforce designed to “address affordability” and improve the company’s
“competitive posture.”
Accord Software and Systems Pvt. Ltd., of Bangalore, India, has announced two new GNSS chips, a system-on-a-chip (SOC) with GPS and integrated peripherals and a GPS/Galileo-comopatible RF front-end chip.
By Inside GNSS
