Global Navigation Satellite Systems Engineering, Policy, and Design
Topcon Positioning Systems (TPS) announced the company’s new CR-G5 high-performance, GNSS choke ring antenna.
Based on the company’s new TA-5 full-spectrum GNSS antenna element, the CR-G5 geodetic antenna offers excellent vertical phase center stability over the GNSS frequency band superior performance in tracking low elevation satellite signals, according to the company.
By Inside GNSS
[Updated February 15, 2012] The GPS community received a Valentine’s Day message from U.S. regulators today (Feburary 14, 2012): there is “no practical way” to mitigate potential interference posed by terrestrial transmissions from LightSquared’s proposed wireless broadband network.
By Inside GNSS
U.S. Deputy Secretary of Transportation John Porcari told a congressional committee today (February 8, 2012) that the expenditure of “substantial federal resources” in assisting LightSquared to gain approval for its terrestrial wireless broadband system was “unusual” yet “merited,” but that “further investment cannot be justified at this time.”
By Inside GNSS
Although it was billed as the strongest for the past eight years and coincided nicely with the American Meteorological Society (AMS) annual meeting in New Oreans, this week’s solar storm apparently had a limited effect on GPS receivers and users.
By Inside GNSS
A Senate investigation into how the Federal Communications Commission (FCC) handled a request to rezone spectrum adjacent to GPS frequencies for LightSquared’s powerful wireless network will continue whether the FCC nixes the plan or not.
Sen. Chuck Grassley, R-Iowa, has been looking into whether the FCC fast-tracked its review of the Virginia firm’s proposal to build a 4G broadband network with signals that would be, tests now show, powerful enough to interfere dramatically with GPS receivers.
By Inside GNSS
In an effort to improve constellation sustainment, on or about Feb. 1, 2012, SVN-49 will resume transmitting an L-band signal using PRN24 as a test asset, according to the U.S. Air Force Space Command. Upon completion of the test event, SVN-49 will once again be decommissioned from active service. PRN24 will then once again be available for future satellite service.
By Inside GNSS
Working Papers explore the technical and scientific themes that underpin GNSS programs and applications. This regular column is coordinated by Prof. Dr.-Ing. Günter Hein, head of Europe’s Galileo Operations and Evolution.
By Inside GNSS
Q: How can pseudorange measurements be generated from code tracking?
A: Every GNSS receiver processes the received signals to obtain an estimate of the propagation time of the signal from the satellites to the receiver. These propagation times are then expressed in meters to solve for the user position using trilateration.
By Inside GNSS
On December 12, 2011, one of the two Galileo in-orbit validation (IOV) satellites launched on October 21 — the Galileo- ProtoFlight Model (PFM) spacecraft — started transmitting its payload signal on the E1 band over Europe.
That same day NavSAS researchers were able to acquire and track the E1 signal (Galileo Code Number 11) beginning at 14:46:15 CET. Two days later, on December 14, the E5 signal became available as well.
By Inside GNSS
When President Obama signed the $1 trillion dollar federal appropriations bill just before Christmas, he also inked into law a provision further protecting GPS receivers from interference from the wireless network proposed by LightSquared.
By Inside GNSS
[Updated January 3, 2012] China released a long-awaited “test version” interface control document (ICD) for its Compass (BeiDou-2) GNSS system today (December 27, 2011). The 11-page publication covers its open B1 civil signal centered at 1561.098 MHz.
By Inside GNSS
The European Space Agency (ESA) has reported its first successful reception of triple-frequency signals from a Galileo in-orbit validation (IOV) spacecraft.
The weekend of December 17 all Galileo signals were activated simultaneously for the first time across the European GNSS system’s three spectral bands, known as E1 (1559–1592 MHz), E5 (1164–1215 MHz), and E6 (1.215–1.300 MHz). The accompanying graphic displays the signals spectral profile.
By Inside GNSS
The Lockheed Martin team developing the U.S. Air Force’s next-generation GPS satellites (GPS Block III) has delivered the program’s pathfinder spacecraft to the company’s Denver, Colorado–area facility.
The program remains on schedule for a 2014 launch of the first Block III space vehicle (SV).
By Inside GNSS
