TAG: GLONASS blackout

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: 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

Faulty Software Determined Cause of GLONASS Failures

April 25, 2014By

The two April failures in Russia’s GLONASS were caused by mathematical mistakes in software, according to Oleg Ostapenko, head of the Russian space agency Roscosmos. Russian newspaper Ria Novosti reported on a press conference where Ostapenko said that programmers who had designed the satellites’ new software had made several mathematical mistakes, but the problem was not major and has practically... read more

This article is tagged with , , and posted in GLONASS, GNSS News, Latest News

GLONASS Failure Inconsequential to Users, Says Russian Press

April 8, 2014By

Reports in the semi-official Russian news daily Izvestia indicate that finger-pointing has gotten underway regarding the April 1 GLONASS systemic blackout, which followed two other high-profile disasters, the destruction-upon-launch of three new GLONASS satellites in July 2013, and the Pacific drowning of three other satellites in December 2010. While we have neither full nor fluent translations from the Russian, we... read more

This article is tagged with , and posted in GLONASS, Latest News

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

GLONASS Gone . . . Then Back

April 2, 2014By
glonass_problem-O

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). This rendered the system completely unusable to all worldwide GLONASS receivers.... read more