National Geodetic Survey Announces National Adjustment of 2011 Project

Friday, May 27, 2011 – As part of the National Geodetic Survey’s (NGS) continuing efforts to improve the National Spatial Reference System (NSRS), we are pleased to announce the National Adjustment of 2011 (NA2011) project. The NSRS is the consistent reference system defining latitude, longitude, height, scale, gravity, and orientation throughout the United States and its territories. NGS maintains and provides access to the NSRS, the foundation for the nation’s transportation, mapping, and charting infrastructure, as well as a multitude of other scientific and engineering applications.

NA2011 will yield updated North American Datum of 1983 (NAD 83) coordinates on approximately 80,000 NGS passive control marks positioned using Global Navigation Satellite System (GNSS) technology. The new adjustment will ensure passive GNSS marks are optimally aligned with the NGS Continuously Operating Reference Station (CORS) network. NA2011 is being done now, because NGS will officially adopt a new set of NAD 83 CORS coordinates in July 2011, as described in the NGS news story, NGS to Update the North American Datum of 1983. More information on the CORS-based realization of NAD 83 is available on the NGS Summary of the Reanalysis of GPS Data (beta) website.

Our goal is to complete the NA2011 project by the end of calendar year 2011. More information on NA2011, including a comprehensive list of Frequently Asked Questions (FAQs), is under development and will soon be available on the NGS website. For more information, contact Michael Dennis.