Category Archives: Surveying

A Re-imagined “24 Miles Round London”

Kristjana Williams, an Icelandic artist who lives and works in London, is fascinated by maps, mythical creatures, and Victorian engravings. She brings historical works of cartography back to life using vibrant, digital collages. Pictured here is her interpretation of Daniel Paterson’s “24 Miles Round London” map, originally published in 1791. Paterson’s map presents London’s surrounding...

A Pennsylvania Traverse Low-Distortion Projection

  This article coincides with the December 2014 xyHt print article, Transformation of Observations – Part 2. In the September 2013 issue of Professional Surveyor is Dr. Charles Ghilani’s excellent article entitled “Grid versus Ground.” The article demonstrates the error created by ignoring elevation in traverse computations and describes the numerical and logical errors inherent...

Artful GNSS

Things in the nation’s capital can happen quickly, but only when the parties involved agree to work closely together towards a common goal. Internationally renowned artist Jorge Rodriquez-Gerada was given six months to develop a plan and complete a six-acre painting using sand and topsoil. His canvas would be an incredibly high-profile piece of National...

What is xyHt?

Stand in the place where you live Now face North Think about direction Wonder why you haven’t before “Stand” – R.E.M. Why an obscure geodetic expression? It’s not all that obscure—it represents a foundational element requisite to nearly all human endeavor. It touches your life explicitly and in the abstract. All of the ways that...

The Coordinate

A steel fence post blended into the backyard, as if it were meant to be there for some purpose, like holding up firewood or stacking lumber. The surveyors—Igor “Eager” (The Kid) Kidinsky and Glenny “Glutton” (The Old Man) Dale—were looking for property pins along the alley, and neither one at first glance recognized this steel...

Canada’s New Vertical Datum: CGVD2013

Geodesy Editor’s Note: The study of Earth’s gravity field is one of the most important aspects of physical geodesy. While seldom mentioned in land surveying text books or discussed at local surveying, mapping, or GIS conferences, it is nonetheless one of the most important issues that geospatial experts deal with on a daily basis.   Changing...