Category Archives: Surveying
![HARN](/wp-content/uploads/2017/07/20170730_123713_resized-272x192.jpg)
Are HARNs on Death Row?
In the late 1980s, the National Geodetic Survey (NGS) launched a program, in cooperation with State partners, to establish a High Accuracy Reference Network (HARN) across the United States. HARN’s History With the rapidly increasing availability and use of GPS equipment, NGS recognized the need to establish a network of high-accuracy, passive survey monuments with...
![Eclipse Background, NASA](/wp-content/uploads/2017/08/Eclipse-Background.tif-272x192.jpeg)
Night in the Afternoon: A US Solar Eclipse
What you need to know about the 2017 solar eclipse The upcoming solar eclipse will leave a 70-mile-wide trail of darkness across the United States on August 21, 2017 (see the map of the eclipse path on pages 44-45). This will be a once-in-a-lifetime event for many people. While another total solar eclipse will make...
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Fire, Ice, and Latitude in Ecuador
A team of U.S. surveyors visited Ecuador to use real-time PPP to pay homage to the 18th-century “Geodesic Mission to the Equator,” one of the most difficult and significant missions in the history of surveying and geodesy. Pictured above: The team of U.S. surveyors on the 2017 Ecuador visit (from back to front): Rich Leu, John...
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Get Ready for the Solar Eclipse!
In less than a month (August 21, to be precise) folks across the United States, from Oregon to South Carolina, will be treated to a rare total solar eclipse. Here’s the Pangaea guide to watching this spectacular event. Safety first! Don’t even think about watching the eclipse without proper eye protection. Retailers have been busy...
![Equations 1-5, Charles Ghiliani, Error Ellipses, xyHt July 2017](/wp-content/uploads/2017/07/Equations.tif-272x192.jpeg)
Error Ellipses
Part 2: Components and Increasing Probability In the previous article (April 2017) I discuss the correlation of the coordinate values for a station and how an error ellipse is used to determine the direction of the largest error at a station. In this article I review the components of an error ellipse, the process that...
![Photo female hands holding modern tablet and man touching screen.Businessmans crew working new investment project office.Using electronic devices. Graphics icons, stock exchanges interface.](/wp-content/uploads/2017/07/unnamed-1-272x192.jpg)
The Elusive Scope: Business Advice for Surveyors
How to prepare for and meet your client’s needs by keeping your eye on the project scope. I wrote many business-advice columns in this magazine’s predecessor, Professional Surveyor Magazine. Now that I’ve adjusted to writing for the entire geomatics world rather than on just surveying issues, I believe I’ve found one topic that affects everyone...