TAG: SVN-49

Disruption in Australia Traced to User Equipment

May 14, 2014By

User equipment incorrectly interpreting data from a satellite set “unhealthy” led to an apparent constellation outage for roughly 1,000 fleet vehicles across Australia in April. The problem was traced to the way a GPS/telecomm chip reacted to an extended navigation test aboard SVN-49, having to do with the recently launched IIF satellite, SVN-64. Although SVN-49 was set unhealthy at the... read more

The System: New Kid on the Block: IIF Readied

March 1, 2010By
It takes four hefty guys to wheel the new satellite along the tarmac, but it will only take one Delta IV rocket to lift it 20,171 kilometers into space on May 13.

The first Block IIF satellite destined for orbit arrived at the Navstar Processing Facility at Cape Canaveral, Florida, aboard an Air Force C-17 cargo aircraft on February 12. It is now undergoing preparations for its launch this spring on a Delta IV rocket. Block IIF will enhance GPS performance by reportedly providing twice the navigational accuracy of heritage satellites, more robust signals for commercial aviation and search-and-rescue, and greater resistance to jamming in hostile environments. Plus: GLONASS, Beidou, Galileo, 24+3 FAQ, and AEP 5.5C software update. read more

This article is tagged with , and posted in The System

Out in Front: An SVN up for Grabs

November 1, 2009By

Wednesday evening, September 23, Savannah, Georgia, 5:30 to 7:00 p.m., Session P2b — a date that will live in GPS history. The 400 to 600 of us who were there to witness it will never forget it. The SVN49 Review Panel. Unprecedented puts it mildly. read more

This article is tagged with and posted in From the Editor

ESRI Conference and SVN-49 Troubles

July 29, 2009By

I had a great visit at the ESRI User Conference earlier this month. If you recall last year, I wrote: “As much as surveyors, engineers, and constructors may not appreciate geographic information systems (GIS) technology, at some point everyone should attend at least the ESRI Survey/Engineering Summit and the first couple of days of the ESRI User Conference held every summer in San Diego, California. This is not a GIS sales pitch. It's a networking sales pitch. When other conferences are struggling to maintain attendance levels, the ESRI conferences seemingly never fail to grow in attendance. This year, it attracted some 15,000 people from 120 countries. That means gobs of GIS people, and also gobs of surveyors and engineers.” The statement rang true this year too. Even in today’s economy where conferences are severely impacted or even cancelled due to travel budget cuts, the ESRI User conference still attracted ~11,000 people this month. read more

This article is tagged with , , and posted in Opinions, Survey

Expert Advice: Cause Identified for Pseudorange Error from New GPS Satellite SVN-49

July 15, 2009By and

The GPS Wing and its contractors have traced the cause of pseudorange errors on L1 and L2 broadcast by the newest GPS satellite, SVN-49, to the manner in which the L5 signal demonstration payload was added to the satellite. Signal leakage between the two input ports of the antenna coupler network for the satellite's array of 12 helical antenna elements, reflected from the L5 filter and then transmitted, creates a second signal with a delay of approximately 30 nanoseconds, and the appearance of a multipath component. While testing an adjustment to the signal-in-space to minimize the effect of the problem on receiver navigation solutions on Earth, the GPS Wing is interested in hearing from manufacturers and the user community concerning the different impacts of SVN-49 signals on the wide range products and applications in operation, before reaching a final decision on what to do with the satellite prior to setting it healthy. read more

This article is tagged with , and posted in Uncategorized