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GPS and Geodetic News You Can Use

2008 Ohio GIS Conference September 10-12, 2008 Crowne Plaza North Hotel Columbus, Ohio. GPS and Geodetic News You Can Use. David Conner Geodetic Advisor to the State of Ohio National Geodetic Survey, NOAA. TOPICS. Overview National Readjustment - NAD83 (NSRS2007)

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GPS and Geodetic News You Can Use

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  1. 2008 Ohio GIS Conference September 10-12, 2008 Crowne Plaza North Hotel Columbus, Ohio GPS and Geodetic News You Can Use David Conner Geodetic Advisor to the State of Ohio National Geodetic Survey, NOAA

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

  3. 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) Example actual horizontal shifts at station SMITH (JY0742) NAD 27 vs NAD 83 (1986) ~ 13 meters NAD 83 (1986) vs NAD 83 (1995) ~ 20 cm NAD 83 (1995) vs NAD 83 (NSRS2007) ~ 1.5 cm

  4. 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 - ?

  5. Ohio’s GPS CORS Network Brought to you courtesy of the ODOT, Bureau of Aerial Engineering VRS/ CORS information Telephone: 614-275-1372, or 614-351-2839. cors@dot.state.oh.us

  6. CORS/OPUS: Overview & Status CORS = Continuously Operating Reference Station The CORS network contains about 1,250 GPS tracking stations, and it is growing by about 200 stations per year. OPUS is a Web-based service enabling users to automatically post-process GPS data.

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

  8. OPUS FLAVORS Try it … http://beta.ngs.noaa.gov/CORS-Proxy/oraOpusDbWeb/

  9. OPUS-DB

  10. OPUS-DBSample Datasheet

  11. OPUS DatasheetConcept

  12. GPS data requirements NGS-modeled antenna • “OPUSable” • 4+ hours of dual frequency data • NGS-calibrated antenna • OPUS must achieve: • ≥ 70% observations used • ≥ 70% ambiguities fixed • ≤ 0.04m peak-to-peak horizontal • ≤ 0.08m peak-to-peak vertical • ≤ 0.03m RMS (4+hr, good stats) GPS data

  13. metadata requirements observationnotes control station description * control stationphoto * antenna type, height *optional for “existing” stations. Simplified bluebooking

  14. NOAA’S County Scorecard • 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) We want YOU to tell us how we’re doing

  15. County Scorecard Details 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? • Is the County in a State that participates in the NOAA State Advisor/Coordinator program? • Has a County Geospatial Representative been identified (eg County Surveyor, County Engineer, GIS Administrator, or equivalent)? • Has “blue book” data from the County been submitted to NGS through activities such as: leveling project software, GPS projects and OPUS DB (when available)? • Has a County Scorecard web survey been filled out by the County Geospatial Representative? • Counties meeting the above criteria are “fully enabled” (shaded green).

  16. NOAA’S County ScorecardHow you can help …

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