Columns and Editorials

GNSS Hotspots | May 2012
May 27, 2012

GNSS Hotspots | May 2012

1. GROWTH SPURT
California/Nevada, USA
√ The age of the Sierra Nevada mountains — home of Yosemite Valley and Lake Tahoe — is puzzling to geodesists. Integrating GPS and inSAR, Universities of Nevada and Glasgow teams studied the area’s uplift and found that it is growing by 1 to 2 millimeters per year. The verdict? The entire range could have arisen in less than 3 million years.

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By Inside GNSS
IP Rights and Wrongs

IP Rights and Wrongs

As Desi Arnaz often said to Lucille Ball during an “I Love Lucy” episode on TV, “You’ve got some ’splaining to do.”

I refer, of course, to the untoward and unexpected initiative by the British Ministry of Defense (MoD) to patent the technical innovations that underlie the planned next generation of civil GNSS signals.

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By Dee Ann Divis
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How do GNSS-derived heights differ from other height systems?
May 24, 2012

How do GNSS-derived heights differ from other height systems?

Q: How do GNSS-derived heights differ from other height systems?

A: Height estimation using GNSS always seems to be trickier than horizontal coordinate estimation.

Why?

On the one hand, the GNSS technique has error sources that are more critical in the vertical direction. Height estimates are weaker because of a combination of satellite geometry, the presence of strong correlations to other parameters, such as atmospheric delays, and the antenna phase center model applied during data analysis.

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By Inside GNSS
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LightSquared Lessons Learned
March 29, 2012

LightSquared Lessons Learned

Oh no! Not another learning experience!

Bumper sticker wisdom after the fact, but better late than never.

As this issue of Inside GNSS heads off to the printer, the regulatory phase of the GPS/LightSquared controversy appears to be winding down, and the litigation phase warming up.

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By Dee Ann Divis
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