Aerospace and Defense

February 29, 2012

GPS Program Budget: A Lot, But Is It Enough?

The details of President Obama’s 2013 budget have been gradually filtering out and, in general, the GPS system and those programs closely linked to satellite navigation, have escaped deep cuts.

On the hardware side the White House has requested $58.2 for GPS IIF satellite procurement. According to Air Force budget documents, the plan is to then wrap up the total IIF procurement of 12 satellites with a request for $77.6 million in FY14 and $7.3 million in FY15.

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By Inside GNSS

Code Tracking and Pseudoranges

FIGURE 2: Pseudorange computation based on transmission. On the left side, the satellites are transmitting mes¬sages synchronously. On the right side, the four subframes are received asynchronously, due to the different propagation time. The TLM word is taken as a referene. The time differences ?i are computed on the basis of the relative arrival times of the front of the first bit of the TLM word.

Q: How can pseudorange measurements be generated from code tracking?

A: Every GNSS receiver processes the received signals to obtain an estimate of the propagation time of the signal from the satellites to the receiver. These propagation times are then expressed in meters to solve for the user position using trilateration.

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By Inside GNSS

New Austerity Squeezes GPS as DoD Tightens Its Belt

Embracing the need for debt-driven discipline, the White House has revised its strategy for the nation’s defense, taking a more fiscally constrained approach that reduces the number of troops and future spending on defense systems.

The new plan, formally announced January 5, was already being put into effect last summer. “The strategic guid­ance was the compass by which we steered the budget review leading to the president’s budget for fiscal year ‘13 and the years thereafter,” Deputy Secretary of Defense Ashton B. Carter told reporters.

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By Dee Ann Divis
January 12, 2012

USAF Awards Lockheed Additional GPS IIIA Satellite Buy

The U.S. Air Force has awarded Lockheed Martin a $238 million contract for production of the third and fourth satellites in the next-generation GPS constellation, known as GPS III.  The acquisition of the next two GPS IIIA satellites at one time will allow the Lockheed Martin-led team to maximize efficiencies in satellite manufacturing.

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By Inside GNSS
November 21, 2011

GNSS Hotspots

One of 12 magnetograms recorded at Greenwich Observatory during the Great Geomagnetic Storm of 1859
1996 soccer game in the Midwest, (Rick Dikeman image)
Nouméa ground station after the flood
A pencil and a coffee cup show the size of NASA’s teeny tiny PhoneSat
Bonus Hotspot: Naro Tartaruga AUV
Pacific lamprey spawning (photo by Jeremy Monroe, Fresh Waters Illustrated)
“Return of the Bucentaurn to the Molo on Ascension Day”, by (Giovanni Antonio Canal) Canaletto
The U.S. Naval Observatory Alternate Master Clock at 2nd Space Operations Squadron, Schriever AFB in Colorado. This photo was taken in January, 2006 during the addition of a leap second. The USNO master clocks control GPS timing. They are accurate to within one second every 20 million years (Satellites are so picky! Humans, on the other hand, just want to know if we’re too late for lunch) USAF photo by A1C Jason Ridder.
Detail of Compass/ BeiDou2 system diagram
Hotspot 6: Beluga A300 600ST

1. Portland, Oregon and Los Angeles, California USA

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By Inside GNSS
November 16, 2011

Oh No! Not LightSquared Again!


Please. Please. Please. 

Can we please talk about something besides LightSquared?

Not yet? You mean, they are still here?

And we have so many other GNSS-related topics that deserve comment: 

Some peculiar cuts in civil GPS funds and GPS III budgets being proposed by congressional committees. 

A re-examination — aka analysis of alternatives — of GPS and PNT options in general. Space weather and an impending solar max. Warrantless GPS-aided tracking before the Supreme Court.

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By Inside GNSS