Improving NGS Products NGS Fall Convocation Holiday Inn – Silver Spring, MD. October 24-28, 2005

1. Improving NGS ProductsNGS Fall Convocation Holiday Inn – Silver Spring, MD.October 24-28, 2005 Earl F. Burkholder, PS, PE New Mexico State University Las Cruces, NM 88003

2. Overview outline - 1 • Introduction • Mission of NGS • History of interaction with NGS • Current status: technology, profession • Current projects at NMSU • Spatial data arena

3. Overview outline - 2 • Relating NGS mission, spatial data arena • NGS products and services include • Forward looking opportunities • Assumptions/consequences • Thank you • Questions/discussion

4. Introduction - EFB • BS Univ. of Michigan 1973 • 5 years at Commonwealth Associates • MS Purdue Univ. 1980 • 1980-1993 teach at Oregon Tech. • Self employed for 5 years • At NMSU since 1998 • On sabbatical, writing book on 3-D

5. Mission of NGS • As stated on web site: “Deliver and evolve the Nation’s foundation of reference for latitude, longitude, height, velocity, (and other things). . .” • Embraced by all team members? • Challenge for management is to establish policies and provide leadership that minimizes default sabotage.

6. History of interaction with NGS • At Commonwealth, I used NGS control. • Oregon Tech, we got NGS support. • Input from NGS for SEWRPC reports. • At NMSU, work with Advisor Bill Stone. • As ASCE Journal Editor, I relied upon NGS for reviews and articles. • Now I’m promoting use of the GSDM.

7. Status of Science/Profession - 1 • Science/instrumentation, digital and 3-D. • Surveying profession – who are the players? - ACSM, diversity and reorganization. - ASCE, focus on engineering applications. - ASPRS, imaging & spatial info society. - FIG, international voice for surveying prof’n. - GITA, represents spatial data users. - IAG, international voice for geodesy.

8. Status of Science/Profession - 2 • Surveying program at NMSU: - Started in 1990 by Dr. James P. Reilly. - Three faculty; Frank, Wurm, Burkholder. - Undergrad only, about 40 students. - Graduates get good jobs; NM & elsewhere - BLM support is vital. NMSU looking for more. - Vendors have been very good to program. (Leica loaned us $240K equipment for a year)

9. Status of Science/Profession - 3 • Work being done by NGS: - Readjusting the spatial network. - Supporting height modernization. - Coordinating use of CORS. - Refining services available using OPUS. - Outreach through state advisors. - Many others

10. 3-D Projects at NMSU • NMSU GPS HARN-based network (illustrates network & local accuracy). • NAVD88 elevation on HARN Station “Reilly” from nearby first-order BMs. • Support of Texas/NM GPS survey of boundary defined by Rio Grande River

14. Rio Grande River Boundary Area

15. State Boundary Example • State boundary between NM and Texas follows Rio Grande River for 25 miles. • River meanders but boundary was “fixed” by U.S. Supreme Court in 1930 on basis of 1929 survey reconstructing 1852 lines. • 105 monuments set in distance of 25 miles. • Current project is to GPS the line. • Horizontal record data are NAD27, Vertical data are NGVD29 (mean sea level).

20. What About Record Accuracy? • Supreme Court Report values: - Horizontal given to .001 seconds (0.03 m) - Vertical given to 0.001 feet (0.0003 m) • Use those as standard deviations • Input into BURKORD9 • Inverse between points for: - Distance = 73.627 m +/- 0.042 m - Azimuth = 44-25-13.42 +/- 118.9 sec.

21. Spatial Data Arena is Huge • ASPRS 10 yr forecast for remote sensing. • ASPRS Panel Report to USGS on National Orthoimagery Program – comments due by October 24, 2005. see www.zianet.com/globalcogo/asprs-comments.pdf • Global Spatial Data Infrastructure (GSDI) purpose is international cooperation and collaboration.

22. Relate NGS Mission to Arena • Define and support National Spatial Reference System. • Develop and promote standards. • Clearing house for implementation of new technology.

23. NGS Services/Products Include • CORS – 3D positions and velocities. • OPUS – Automated processing for users. • Height Modernization – geoid modeling. • Standards – Network and local accuracy. • Outreach to: - Other federal agencies - State and local agencies - Professional organizations

24. Forward Looking Opportunity - 1 • Height – If data from all satellites are used on a deformable Earth, then vertical may turn out to be the strongest component. - Involves interpolation in radial direction. - Requires simultaneous data from all GPS satellites to worldwide network. - GSDM provides appropriate computational environment to do it.

25. Forward Looking Opportunity - 2 • Ellipsoid height is adopted as elevation. - Reduces the need for geoid modeling. - Hydraulic head is not given by orthometric heights. - Use time analogy with local noon. • ACSM articles on heights. • www.zianet.com/globalcogo/elevgsdm.pdf

26. Forward Looking Opportunity - 3 • Orthophoto map is produced by plotting local differences with respect to origin selected by the user. - Presumes each pixel has ECEF coordinates and covariance. - That means raster file is converted to a vector file? - Totally impractical due to storage req’d?

28. Assumptions • Spatial data are digital and 3-D. • There must be a single origin for 3-D data. • ECEF geocentric system is foundation. • Spatial data are obtained from physical observations reduced to components. • Strict hierarchy for primary/derived data. • Spatial data accuracy is given by standard deviations – component by component.

29. Consequences • Need to make distinction between measurement and observation. • Need to understand and honor difference between direct & indirect measurements. • Some spatial data are relative and some are absolute. It makes a difference. • Local & network accuracy are both legitimate. Local accuracy is based upon storing and using correlation.

30. Thank you! • Truly grateful for opportunity to share. • Sabbatical is going well. Lots yet to do. • Windows-based BURKORD™ software is coming along. Will be gratis with book. • Publisher not yet chosen. • Back in classroom August 2006. • www.zianet.com/globalcogo/status.html .