Archives

GPS, GLONASS, and SBAS Webinar Follow-up

May 20, 2010 - By

Normally, my column following a webinar is dedicated to Q&A follow-up from the webinar. However, immediately following the April 22 webinar, I traveled to Phoenix, Arizona, to attend the ACSM/GITA conference, which I wrote about earlier this month. read more

This article is tagged with and posted in Newsletter Editorials, Opinions, Survey, Survey Scene

Carrier-Phase Anomalies Detected on SVN-48

May 17, 2010 - By

By Brady O’Hanlon, Mark L. Psiaki, Paul M. Kintner Jr., and Steven P. Powell Anomalous behavior of the L1 C/A-code carrier phase has been detected on PRN07/SVN-48. The anomalies are sudden step-like changes of phase by about 10 degrees/5 millimeters. These steps are followed by negative steps of the same magnitude that restore the original phase time history. These anomalous... read more

This article is tagged with , and posted in GNSS, GPS Modernization

ACSM/GITA Conference Coverage

May 4, 2010 - By

The annual ACSM (American Congress on Surveying and Mapping) isn’t what it used to be. Attendance was way down and the number of exhibitors is way down. The technical content, however, was still pretty good. In fact, I've included links to several videos I recorded at the ACSM/GITA conference. read more

This article is tagged with and posted in Newsletter Editorials, Opinions, Survey, Survey Scene

Part 1: The Origins of GPS, and the Pioneers Who Launched the System

May 1, 2010 - By

The original system study, the key innovations, and the forgotten heroes of the world’s first — and still greatest — global navigation satellite system. True history, told by the people who made it. Part One of a Two-Part Special Feature. read more

The System: Galileo ICD, Free at Last

May 1, 2010 - By

Galileo ICD, Free at Last The European Commission (EC) has published an updated Galileo Open Service Signal-In-Space Interface Control Document (OS SIS ICD) giving technical specifications and performance expectations for the future system. As reported by GPS World in October 2009, the EC will not charge for manufacturing licenses. No fees will be required for manufacturers to design, develop, make,... read more

This article is tagged with , and posted in Augmentation & Assistance, Galileo, GNSS, The System

Innovation: Accuracy versus Precision

May 1, 2010 - By

A Primer on GPS Truth
True to its word origins, accuracy demands careful and thoughtful work. This article provides a close look at the differences between the precision and accuracy of GPS-determined positions, and should alleviate the confusion between the terms — making abuse of the truth perhaps less likely in the business of GPS positioning. read more

This article is tagged with and posted in Algorithms & Methods, Innovation

Commanding Conversation

May 1, 2010 - By

Defense editor Don Jewell is a retired Air Force officer who served for 30 years; many of his former peers and contemporaries are currently senior officers in today’s U.S. Air Force. Don sat down recently with General C. Robert Kehler, Commander of the U.S. Air Force Space Command, whom he has known and worked with for more than 20 years, to discuss GPS from the four-star point of view. read more

This article is tagged with and posted in Defense, GPS Modernization