Tag Archives: geodesy

GEOID18: Make Your Mark and Improve Your Heights

As a community, we have the unique opportunity to contribute to the densification and improvement of our national geoid model and vertical transformation tools in support of the ongoing modernization of the National Spatial Reference System (NSRS). While the geoid model is a national level product, the impacts of this work are directly felt within...

xyht 2022

2022: Monumental Changes, Part 1

The National Geodetic Survey of the U.S. responds to surveyors’ questions on how legacy physical geodetic monuments will be affected by the planned 2022 reference framework modernization. Editor’s note: A recent article in xyHt’s online newsletter, Field Notes, prompted a discussion among surveyors on the pending 2022 modernization of the National Spatial Reference System (NSRS) for...

xyHt August

xyHt Magazine August 2017 Issue

To view this issue as it appears in full in print, click the cover: Below are featured articles from the issue on our website: Editorial Fire, Ice, and Latitude in Ecuador Nicholls State University Geomatics Program Photogrammetric Engineering at The National Polytechnic Institute Drones and Surveying Flood Zones Controlling the Future with Training Women in...

Equations 1-5, Charles Ghiliani, Error Ellipses, xyHt July 2017

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...

Weekly xyHt News Links: 6/16/17

RIEGL has received the Sebastian Sizgoric Technical Achievement Award at this year’s JALBTCX conference in Savannah, Georgia.  Record attendance for GEO Business 2017 Identified Technologies Aligns with DJI to Offer Best-in-class Commercial Drone Solution Survey and Mapping Company Partners with Leading Unmanned and Manned Flight Service Experts Aeroscout launches UAV helicopter for high-altitude flight Congress increases funding...

Foundations for Computing Error Ellipses, figure 2

Part 1: Foundations for Computing Error Ellipses

Standard Error Rectangle and Error Ellipse What is an error ellipse? One of the advantages of a least-squares adjustment over other methods is that a byproduct of the adjustment is not only the most probable values for the unknown coordinates but also standard deviations on these values Suppose for a moment that we are computing...