Aerospace and Defense

August 24, 2010

CDR Passed: GPS III Ready for Build Phase

Artist’s rendering of GPS III satellite. Lockheed Martin image

More than two years into a multi-billion-dollar contract, the Lockheed Martin team developing the U.S. Air Force’s next-generation GPS Block III satellites continues to defy the physics of large aerospace programs by successfully completing the program’s Critical Design Review (CDR) phase last week — two months ahead of the baseline schedule.

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By Inside GNSS
August 19, 2010

Air Force Approves 3 GPS Technical Specs

The GPS Wing has authorized publication of three technical documents with updated specifications for the U.S. Global Positioning System, including the next-generation GPS Block IIIA satellites now in development, the L5 radio link, and the new L1 civil signal  (L1C) that will be available with the GPS III spacecraft.

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By Inside GNSS
July 16, 2010

Lockheed Martin Unveils GPS Exhibit at the United Nations in Vienna

Rick Ambrose, Lockheed Martin vice-president and general manager, surveillance and navigation systems, introduces GPS Block III model for Permanent Space Exhibit at United Nations Committee on Pea, Vienna,

Lockheed Martin has opened a GPS exhibit as a part of the Permanent Space Exhibit of the United Nations Office at Vienna, Austria, to emphasize the importance of satellite navigation technology serving millions of citizens around the globe.

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By Inside GNSS
June 22, 2010

Lockheed Martin Team Completes Requirements Review for GPS IIIB Program

Lockheed Martin has announced successful completion of a key requirements review for the GPS IIIB satellite series under the U.S. Air Force’s next-generation GPS III Space Segment program.

Lockheed Martin Space Systems, Newtown, Pennsylvania, is working under a $3 billion development and production contract from the U.S. Air Force to produce up to 12 GPS IIIA satellites, with first launch projected for 2014. The contract includes a Capability Insertion Program (CIP) designed to mature technologies and perform rigorous systems engineering for the future IIIB and IIIC increments planned as follow-on procurements.

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By Inside GNSS

On the Air

With the launch of the Delta IV rocket on May 27 from Cape Canaveral Air Force Station the first satellite (space vehicle number 62 or SVN62) of the latest GPS generation Block IIF (F, for “follow-on”) was carried into earth orbit — a major step with roots in the past.

Eight years ago in August 2002 the United States decided in coordination with the International Telecommunication Union (ITU-R) to transmit a new civil signal on a third frequency known as L5.

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By Inside GNSS
June 15, 2010

ITT Passes GPS III Nav Component CDR

ITT Corporation has announced that it passed a key milestone last month with successful completion of the critical design review (CDR) for the Mission Data Unit (MDU) the company is developing as part of the navigation payload for the U.S. Air Force’s GPS III program.

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By Inside GNSS
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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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