Category Archives: Surveying
Closer Than It Looks
Above: High-definition mapping sensors (lidar, digital, and oblique imagery, here mounted on a helicopter during collection of an autonomous vehicle mapping project) provide an accurate, cost-effective approach to limit the interference and potential delays related to collecting extensive control on a right of way. A hybrid of geospatial technologies could help autonomous vehicle mapping drive...
A Correctly Weighted Least Squares Adjustment, Part 3
Estimating Standard Errors in Angular Observations In the previous articles (January and February 2016) I discuss the unreliability of standard deviations when they are computed from a small sample of observations, as well as how to estimate errors in centering an instrument over a well-defined point and how to estimate the standard error for electronically...
Multiple Choices
Forum on the Future of Surveying enters its initial feedback phase. This new column provides monthly coverage of the Forum on the Future of Surveying (FFOS)—a national initiative with representatives from 15 key surveying-related associations—to examine paths forward for the profession. See the first installment in our March issue. Now the initial report of the...
Fill out the Future of Surveying Questionnaire
Invest some time in the future of the profession – fill out the questionnaire! A monthly column in xyHt continues provide coverage of the Forum on the Future or Surveying (FFOS); a national initiative with representatives from 15 key surveying related associations to examine paths forward for the profession. See the first installment in our...
Book Review of Dr. Herbert Stoughton’s Journeys
Book Review Journeys: One Individual’s Excursions into the Surveying and Mapping Professions by Dr. Herbert Stoughton I have the honor and a pleasure to review the book referenced above, which I am going to call Journeys, and which was authored (at the request of the Professional Land Surveyors of Wyoming West Chapter) by Herbert W....
“Sea Level Datum of 1929” — Did You Know?
I recently was consulted about the use of the term “Sea Level Datum of 1929” on plans and in engineering reports dating from the 1940-60s. The inquirer was concerned that this possibly meant that the work was based on something other than the National Geodetic Vertical Datum of 1929 (NGVD 29). As is often the...
