Aerospace and Defense

May 31, 2010

Deselecting Unavailability

Only a decade ago, but a world away: 2000.

The last year of the old century that everyone thought was the first of the new.

When flying was still a delight, rather than a worrisome bother.

When the expected — a global Y2K bug–bitten IT meltdown — didn’t happen, and the much-anticipated but still-unexpected did: the United States turned off GPS selective availability.

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By Inside GNSS
May 16, 2010

The GPS Assimilator

For the complete story, including figures, graphs, and images, please download the PDF of the article, above.

What will GNSS receivers look like five years from now? 

The answer, of course, depends on the application. Mass-market receivers used in applications that do not require precision positioning and timing (hand-held units for hikers, for example) will likely remain simple, single-frequency L1 C/A-code–based GPS devices.

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By
April 10, 2010

U.S. Invites Comments for Easing GPS SVN49 Signal Anomaly

(This article first appeared in the March 31 Inside GNSS SIGNALS eNewsletter)

The GPS Wing is in the middle of a yearlong process designed to sort out the trade-offs among a set of at least nine options that may be undertaken to reduce the effects of a signal anomaly on the GPS satellite known as SVN49.

In a March 26 teleconference, the first of two scheduled to discuss the options, Lt. Col. James Lake, the wing’s deputy chief engineer, emphasized that some of the options could well improve the performance of some receivers while decreasing that of others.

He underlined the Air Force’s concern that receivers that don’t conform to the specification for GPS space segment/navigation user interfaces (IS-GPS-200) "greatly complicate the issue."

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By Inside GNSS
March 31, 2010

U.S. Air Force Invites Comments for Easing GPS SVN49 Signal Anomaly

The GPS Wing is in the middle of a yearlong process designed to sort out the trade-offs among a set of at least nine options that may be undertaken to reduce the effects of a signal anomaly on the GPS satellite known as SVN49.

In a March 26 teleconference, the first of two scheduled to discuss the options, Lt. Col. James Lake, the wing’s deputy chief engineer, emphasized that some of the options could well improve the performance of some receivers while decreasing that of others.

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By Inside GNSS
March 26, 2010

IET Seminar: GNSS-10, The Future of Satellite Navigation

The UK Institution of Engineering and Technology will sponsor a one-day seminar on Galileo and GNSS on Thursday, April 29 at the IET headquarters on the Thames Embankment,  Savoy Place, London.The event runs from 9 A.M. to 5 P.M.

Speakers include GNSS experts EADS Astrium, Helios, Roke Manor Research Ltd, SSTL, Logica and University College London.

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By Inside GNSS

DoT Seeks Help from Receiver Manufacturers to Decide on GPS SVN49 Mitigation

[Updated March 27] The first of two  teleconferences hosted by the GPS Wing underlined the U.S. Air Force’s desire to gain greater participation by manufacturers of user equipment in sorting out the options for mitigating the effects of a signal anomaly on the GPS satellite known as SVN49.

The March 26 teleconference, held on the same day as publication of a notice in the Federal Register inviting public comment on nine possible options for dealing with the anomaly, drew only a handful of participants. But the U.S. Department of Transportation Research and Innovative Technology Administration (RITA), which issued the invitation, and the GPS Wing, which has the lead in implementing an eventual decision, hope to see further industry participation in written comments and a second teleconference planned for April 30.

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By Inside GNSS
February 26, 2010

Raytheon Wins $1.5-Billion GPS OCX Contract

Raytheon Corporation graphic

Officials from the Space and Missile Systems Center’s Global Positioning Systems Wing announced today (February 25) the award of the Next Generation GPS Control Segment (OCX) contract to Raytheon Company, Intelligence & Information Systems, Aurora, Colorado.

With a baseline duration of 73 months, the OCX development contract has option years for sustainment worth a potential total of $1,535,147,916. Raytheon teammates include Boeing, ITT, Braxton Technologies, Infinity Systems Engineering, and the Jet Propulsion Laboratory.

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By Inside GNSS
February 16, 2010

Ready to Navigate!

After three decades of increasingly widespread use, satellite navigation-based services have changed significantly, especially for general users in the mass market. New technology enablers such as assisted GPS (A-GPS), the use of massively parallel correlation, and the application of advanced positioning techniques have significantly enhanced the time-to-first-fix (TTFF) and sensitivity of today’s receivers.

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February 11, 2010

First GPS Block IIF Satellite Moves to Cape Canaveral: Launch Window Opens Mid-May

First Block IIF Satellite (Boeing)

[updated Februaary 16] The first Block IIF satellite is undergoing final launch preparations after arriving at Cape Canaveral Air Force Station in Florida aboard a Boeing-built C-17 Globemaster III airlifter.

Space Vehicle 1 (SV-1), the first of 12 GPS IIF satellites for the U.S. Air Force, will lift off on a United Launch Alliance Delta IV vehicle later this year, with the first launch window in mid-May.

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By Inside GNSS