GPS and Geodetic News You Can Use

2. TOPICS Overview National Readjustment - NAD83 (NSRS2007) GPS CORS, OPUS, OPUS-DB, and more County Scorecard

4. The CEAO Board, on Sept 6, 2007, passed a resolution to �Adopt NAD83 (NSRS2007) as the reference system of choice for the development of county coordinate systems� in Ohio.

6. Shifts in Ohio NAD 83 (1995) vs NAD 83 (NSRS2007) Horz Shift Average : 0.016 m (Max: 0.348 m) Vert Shift Average : 0.013 m (Max: 0.503 m)

7. For Stations not IncludedIn the NSRS (2007) readjustment NGS recommends that NAD 83 data that is not part of the NSRS readjustment be readjusted using original observation data Because of the relatively small shifts involved transformation software such as NADCON will not be developed for NAD 83(NSRS2007) NADCON accuracy ~ 6 cm (0.2 ft) NAD 83 (NSRS2007) avg shift ~ 2.5 cm NGS will streamline the process of project acceptance OPUS DB � coming soon - ? NADCON transformation value accuracy of 0.06 meter +/- 0.02 meter (0.20 +/- 0.06 feet) NAD 83(NSRS2007) shifts across Ohio average 1.6 cm New NGS Announcement, April 2007: The Products and Services Committee of NGS voted to rescind the 1998 NGS policy which stated that a transformation would be provided between older versions of NAD 83 and NAD 83(NSRS2007). Initial tests indicated that the shifts were too small, the accuracy of the shifts too large, and sparseness of the data too great to produce a useful transformation. � Users who wish to transform existing surveys from an older version of NAD 83 into NAD 83(NSRS2007) are urged to recompute coordinates using original observations and newly published NAD 83(NSRS2007) coordinates.NADCON transformation value accuracy of 0.06 meter +/- 0.02 meter (0.20 +/- 0.06 feet) NAD 83(NSRS2007) shifts across Ohio average 1.6 cm New NGS Announcement, April 2007: The Products and Services Committee of NGS voted to rescind the 1998 NGS policy which stated that a transformation would be provided between older versions of NAD 83 and NAD 83(NSRS2007). Initial tests indicated that the shifts were too small, the accuracy of the shifts too large, and sparseness of the data too great to produce a useful transformation. � Users who wish to transform existing surveys from an older version of NAD 83 into NAD 83(NSRS2007) are urged to recompute coordinates using original observations and newly published NAD 83(NSRS2007) coordinates.

8. Ohio�s GPS CORS Network

9. CORS/OPUS: Overview & Status

10. Vertical standard error achievable when a user submits 15 minutes of GPS data to OPUS-RS

11. OPUS FLAVORS Please check out NGS' new secret (NOT for general distribution) website for DRAFT OPUS developments http://beta.ngs.noaa.gov/OPUS/ "Not for General Distribution" means this is a developmental product we are not ready to post to the public on our regular homepage. *OPUS-DB**:* This prototype NGS database for sharing your OPUS results continues to mature. A new datasheet retrieval page, simplified registration, and upload page are now available. Please feel free to submit data and note any usability concerns. See also our sample datasheet <http://beta.ngs.noaa.gov/CORS-Proxy/oraOpusDbWeb/getDatasheet.jsp?PID=OP073 45143452&style=modern>. *OPUS-mapper:* Developed for the US census, this uses lower accuracy, short-duration kinematic or stop-and-go observations from single- or dual-frequency receivers. *OPUS-projects:* For internal NGS-trial only; may facilitate management and processing of multiple-receiver campaign surveys. General OPUS usage patterns are described in our CORS newsletter: http://www.ngs.noaa.gov/CORS/newsletter1/ Please check out NGS' new secret (NOT for general distribution) website for DRAFT OPUS developments http://beta.ngs.noaa.gov/OPUS/ "Not for General Distribution" means this is a developmental product we are not ready to post to the public on our regular homepage. *OPUS-DB**:* This prototype NGS database for sharing your OPUS results continues to mature. A new datasheet retrieval page, simplified registration, and upload page are now available. Please feel free to submit data and note any usability concerns. See also our sample datasheet <http://beta.ngs.noaa.gov/CORS-Proxy/oraOpusDbWeb/getDatasheet.jsp?PID=OP073 45143452&style=modern>. *OPUS-mapper:* Developed for the US census, this uses lower accuracy, short-duration kinematic or stop-and-go observations from single- or dual-frequency receivers. *OPUS-projects:* For internal NGS-trial only; may facilitate management and processing of multiple-receiver campaign surveys. General OPUS usage patterns are described in our CORS newsletter: http://www.ngs.noaa.gov/CORS/newsletter1/

12. OPUS-DB

13. OPUS-DBSample Datasheet

15. GPS data requirements

16. metadata requirements

18. NOAA has a relatively new performance metric that assesses how well we are doing at �enabling� local capacity for accurate positioning. This metric: Makes use of NOAA�s Online Positioning User Service (OPUS) as a proxy to assess the local use of NOAA positioning tools and services. Was developed over the past several years in partnership with National Association of County Surveyors (NACS). Involves the use of a web-based county scorecard of 23 survey questions specifically focusing on infrastructure, NGS models and tools, NGS capacity building and outreach, and overall satisfaction. We need input from YOU, our core customers, to help NOAA improve its geospatial products and services. For more information, visit http://www.ngs.noaa.gov/scorecard/ or contact: Your NOAA State Geodetic Advisor, in Ohio Dave.Conner@noaa.gov (for current list of all Advisors visit http://www.ngs.noaa.gov/ADVISORS/) OR Brett Howe (Brett.Howe@noaa.gov) NOAA�S County Scorecard

19. Our Performance Metric Asks Are Counties using NOAA�s positioning products and services? NOAA looks at County Online Positioning User Service (OPUS) use as a proxy. Have there been 25 or more OPUS solution generations in a given county in the last 12 months? Counties meeting the above criteria are �substantially enabled� (shaded yellow). Is there feedback and interaction between the local community and NOAA?

20. NOAA�S County ScorecardHow you can help �

24. NSRS Coordinate Systems Latitude & Longitude State Plane Coordinates UTM Coordinates U.S. National Grid Earth-Centered Earth-Fixed NAD 83 NAD 27 NAVD 88 NGVD 29 ITRF00 ITRF05 What would happen if a community received multiple warnings?What would happen if a community received multiple warnings?

25.  Coordinate Confusion

26.  What�s A Person To Do? NGS Ten Year Plan, Page 11 (Provide access to the NSRS) �NGS also recognizes that many users work in various datums and reference frames and that it must provide tools for these users. NGS will therefore publish all coordinates and velocities of NSRS defining points in both the most recent official U.S. Datums and the most recent realization of the International Terrestrial Reference Frame (ITRF). Furthermore, NGS will provide simple transformation tools between all historic and current datums and reference frames used by NGS, in 4 dimensions if possible.�NGS Ten Year Plan, Page 11 (Provide access to the NSRS) �NGS also recognizes that many users work in various datums and reference frames and that it must provide tools for these users. NGS will therefore publish all coordinates and velocities of NSRS defining points in both the most recent official U.S. Datums and the most recent realization of the International Terrestrial Reference Frame (ITRF). Furthermore, NGS will provide simple transformation tools between all historic and current datums and reference frames used by NGS, in 4 dimensions if possible.�

27. HTDP NAD_83(CORS96) to WGS-84(original)

28. HTDPNAD_83(CORS96) to WGS-84(original)

29. The NGS 10 year plan

30. Gravity for the Re-definition of the American Vertical Datum Official NGS policy as of Nov 14, 2007 $38.5M over 10 years Airborne Gravity Snapshot Absolute Gravity Tracking Re-define the Vertical Datum of the USA by 2017 Q: What is GRAV-D?A: A Plan (released Dec 2007)

31. The first, middle and last point of GRAV-D: Gravity and Heights are inseparably connected Or (to borrow from a common bumper sticker): No gravity, no height Know gravity, know height http://www.ngs.noaa.gov/GRAV-D/ Q: What is GRAV-D?A: Gravity to determine heights accurately

32. Fast, Accurate Orthometric Heights GPS already gives fast accurate ellipsoid heights If the geoid were determined to highest accuracy� Voila� Fast, accurate orthometric heights Anywhere in the nation Time-changes to H determined through: GPS on CORS (h changes) Absolute gravity spot checks (N changes)

33. GRAV-D Airborne gravity Critically needed as a one-time high resolution �snapshot� of gravity in the USA As opposed to the thousands of surveys, with hundreds of instruments and operators over dozens of years One time survey Absolute gravity Cyclical for episodic checks in fixed locales Co-incident with foundation CORS? Two field meters plus one fixed SG Relative Gravity More frequently attached to �Height Mod� surveys

34. National Readjustment

35. National Readjustment

36. New Standards for Geodetic Control Local accuracy ----------- Relative to Adjacent Points Network Accuracy ------- Relative to CORS Both are relative accuracy measures at 95% confidence Will not use distance dependent (proportional) expression of accuracy Order/Class codes (A, B, 1, etc.)

37. Example Datasheet with new Accuracies

38. FGDC Standards for Geodetic Control

39. Future Changes? The published CORS coordinates based on ITRF2000 define the new NAD 83 (NSRS2007) coordinate system When the next version of ITRF is available NGS will probably adopt it and revise the CORS coordinates � within a couple of years Question- With Absolute antenna calibrations now implemented with ITRF05, what effect will this have on previously reduced vectors which used relative antenna calibrations when combined with new reductions?Question- With Absolute antenna calibrations now implemented with ITRF05, what effect will this have on previously reduced vectors which used relative antenna calibrations when combined with new reductions?