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Learn about the latest updates and offerings from the National Geodetic Survey (NGS) at the Michigan Society of Professional Surveyors Annual Meeting. Discover new tools and services such as VDatum, DSWORLD, GRAV-D, and more. Find out about the future plans and the NGS 10-Year Plan.
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Update on NGS Products and Services Michigan Society of Professional Surveyors 69th Annual Meeting Lansing, MI February 25th 2010
New and Updated Products & Services • VDatum – Replaces the IGLD85 Tool • DSWORLD • GRAV-D • Windesc • Translev • LOCUS - (Leveling Online Computing Service) • OPUS - (Online Positioning User Service) • GEOID09 • Corbin Learning Center
Future • NGS 10 Year Plan NGS10yearplan.pdf • Online Processing Services to replace “Blue Booking” • Survey mark descriptions “al a carte”. • CBL’s
Reasons for replacing NAD 83 with a geocentric reference system Ellipsoid heights can be converted to corresponding orthometric heights in the proposed new U.S. geopotential datum via the equation H = h – N where N is based on a true gravimetric geoid Geocentric coordinates would closely approximate WGS 84 coordinates (WGS 84 is an extremely popular reference system because it is the underlying reference system for GPS) Geocentric coordinates would closely approximate ITRF coordinates which is popular within the scientific community The Wide Area Augmentation System (WAAS) uses ITRF Other Countries have adopted a geocentric reference system
Reasons for staying with NAD 83 • State Plane Coordinates are based on NAD 83 • Legislation in 48 states requires the use of NAD 83 • The NGS Integrated Data Base (NGSIDB) contains only NAD 83 coordinates for more than 300,000 passive reference stations • Perhaps several million passive reference stations in the U.S. (in addition to those archived in the NGSIDB) have only NAD 83 coordinates • Many GIS’s and maps are based on NAD 83 coordinates • A significant amount of imagery is tied to NAD 83 coordinates • The Nationwide Differential GPS service uses NAD 83
NGS Mission Statement “To define, maintain and provide access to the National Spatial Reference System to meet our nation’s economic, social, and environmental needs” Questions?