GNSS

AGU concerned over US limits to science communication

January 26, 2017By

The American Geophysical Union (AGU) wrote to U.S. federal agency heads on Jan. 26, in response to reports that the administration under President Donald Trump has instructed federal agencies to stop communicating with the media, policymakers and the public. “The signals are not encouraging, and they’re alarming, and they’re causing a lot of fear in the scientific community,” Christine McEntee,... read more

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CNN explores space warfare, US military’s use of GPS

January 26, 2017By

A spaceborne laser zaps a GPS satellite, disabling it. A “kamikaze” satellite hits and destroys other nations’ critical satellites. Another satellite moves beside an Intelsat bird — and listens in. A new CNN special considers all of these possibilities in an exploration of an arms race in space, showcasing the devastation that would be caused by space warfare and how the... read more

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Implications of BeiDou explored in US congressional report

January 25, 2017By

The U.S.-China Economic and Security Review Commission has issued a staff report titled “China’s Alternative to GPS and Its Implications for the United States.” The report examines the objectives behind Beijing’s decision to develop the system as an alternative to GPS, its efforts to build an industry around the system, and the effects this might have in security, economic and diplomatic... read more

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USAF to test increased GPS signal power Jan. 25

January 24, 2017By

Beginning Wednesday, Jan. 25, Air Force Space Command (AFSPC) will conduct a limited-duration test implementing an increase of the Ll C/A power level on the GPS Block IIR-M and llF satellites — a total of 19 satellites. The C/A power will remain within IS-GPS-200-H specifications, and the power increase is not expected to increase the noise floor by more than... read more

Galileo clock anomalies under investigation

January 19, 2017By

The European Space Agency (ESA) issued a press release addressing the Galileo clock failures reported Jan. 18. GPS World Innovation editor Richard Langley provided the following summary of the satellites and clocks involved, based on information we have received to date. 5 satellites affected: 3 IOVs, 2 FOCs Total of 10 failures; 1 fixed; so 9 continuing failures 5 masers... read more

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Qualcomm Research: Robust positioning from visual-inertial and GPS

Presented at ION GNSS+, September 2016 GPS positioning in urban scenarios is challenging because of large numbers of non-line-of-sight outlier measurements. We propose a robust positioning algorithm that combines GPS observations with visual-inertial odometry information to handle such outliers. We demonstrate the effectiveness of our algorithm in a simulation scenario with close to 80-percent outliers. In experiments in a mild... read more

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Clocks fail on some Galileo satellites, backups working

January 18, 2017By

Clocks have failed onboard several Galileo satellites in space, reports Phys.org, a web-based science, research and technology news service. The cause of the failure is being investigated, European Space Agency director general Jan Woerner told journalists in Paris on Wednesday. Each Galileo satellite has four atomic timekeepers — two rubidium and two hydrogen maser. Three rubidium and six hydrogen maser clocks are not... read more

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Indian government warns airlines to use GAGAN

January 17, 2017By

The government of India has warned domestic airlines of “consequences” if they do not use GAGAN, the state’s GPS-Aided Geo Augmented Navigation system, reports the Mumbai Mirror. The warning came during a meeting called by the Directorate General of Civil Aviation (DGCA) in December with all stakeholders, including the airlines. Most aircraft registered in India are still not equipped with... read more

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