System and Business News

The System: GLONASS in April, What Went Wrong

June 24, 2014By
Figure 1. Affected broadcast messages for each GLONASS satellite. Colors indicate the different orbit planes.

By Gerhard Beutler, Rolf Dach, Urs Hugentobler, Oliver Montenbruck, Georg Weber, and Elmar Brockmann What Happened: On April 1, 2014, at 21:15 UTC, all GLONASS satellites started to transmit wrong Broadcast Messages (BM) as previously reported by GPS World. The satellite positions derived from these BM were wrong by up to ± 200 kilometers in each of the three coordinates... read more

The System: Sixth GPS IIF Launched into Orbit

June 1, 2014By
Photo credit: United Launch Alliance.

A sixth GPS IIF satellite was launched aboard a United Launch Alliance Delta 4 rocket from Cape Canaveral at 8:08 p.m. EDT May 16. The satellite, designated GPS IIF-6 and built by Boeing, is one of the next-generation GPS satellites, incorporating improvements to provide greater accuracy, increased signals, and enhanced performance for users. According to Boeing, each GPS IIF satellite... read more

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GPS/GLONASS Dispute: CEO Clarifies Misunderstandings

May 23, 2014By
LD-Javad

“Use any opportunity to create friendship and peace,” urged Javad Ashjaee, president and CEO of JAVAD GNSS, in a May 23 conversation with journalists. He decried the recent controversy about monitoring stations on both U.S. and Russian soil, saying it was based in misinformation and misinterpretations, inflated by a political crisis in a completely different area. “This [GNSS] is a... read more

The System: GLONASS Fumbles Forward

May 1, 2014By
GLONASS PLOT from the Roscosmos GLONASS Information-Analytical Centre, showing the 12-hour outage, with full service eventually restored on April 2.

Two April Disruptions Furnish Fodder for Multi-GNSS Receivers and Alternative PNT In an unprecedented total disruption of a fully operational GNSS constellation, all satellites in the Russian GLONASS broadcast corrupt information for 11 hours, from just past midnight until noon Russian time (UTC+4) on April 2 (or 5 p.m. on April 1 to 4  a.m. April 2, U.S. Eastern time).... read more

Protect, Toughen, Augment: Words to the Wise from GPS Founder

April 15, 2014By
Brad Parkinson

“What can we do to reduce the vulnerability [of GPS] and ensure that the expectations of the public are going to be met?” asked Dr. Bradford Parkinson as he opened his presentation this morning (Tuesday, April 15) at the European Navigation Conference, ENC-GNSS 2014 in Rotterdam, The Netherlands. Parkinson went through his 61-slide, 50-minute briefing on what he called “PTA”... read more

Locata Warns: Lessons to Be Learned from GLONASS Spasm

April 15, 2014By
Locata-O

Calling it an “unprecedented and deeply worrying total disruption . . . [that] shook the industry,” Locata Corporation reiterated its call for redundant terrestrial systems to back up GNSS in the wake of the April 1 11-hour GLONASS system outage. Nunzio Gambale, Locata CEO, said “We have been telling the industry for years that you cannot have a critically important... read more

Altus Positioning Systems Pinpoints Cause for GLONASS Default

April 4, 2014By

Regarding the April 1–2 11-hour downtime for the full GLONASS constellation, president and CEO Neil Vancans of Altus Positioning Systems provides this additional information: “From the reports on GLONASS problems, we have an explanation that may be used in our technical support replies: “Our analysis reveals the GLONASS integration algorithms skipped an interval of around 1.5 minutes at the control... read more

How to Survive a Total Constellation Outage

April 3, 2014By
Broadcom-O3

Yesterday we posted news of an 11-hour downtime for the full GLONASS constellation, due to an upload of bad ephemerides. Coincidentally, during that 11-hour period, the mass-market chip company Broadcom was conducting multi-constellation receiver tests in Asia. Frank van Diggelen, Broadcom’s chief GNSS scientist and vice president says, “We have definitive data to show how a multi-constellation receiver survives such... read more