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2012 PLSC Track, Datums and tools to connect geospatial data accurately, Pamela Fromhertz
The document discusses geodetic datums and their importance in accurately connecting geospatial data, including various types of datums and GPS accuracy. It elaborates on the National Spatial Reference System (NSRS) managed by NOAA, which supports various applications like nautical charts and flood zone mapping. Furthermore, it highlights advancements in geodetic control, including recent updates to datums and tools for improved positioning and data accuracy.
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2012 PLSC Track, Datums and tools to connect geospatial data accurately, Pamela Fromhertz
- 1. Datums and Toolsto Connect Geospatial Data Accurately Pamela Fromhertz Colorado State Geodetic Advisor National Geodetic Survey National Oceanic and Atmospheric Administration GIS in the Rockies September 20, 2012 Denver, CO
- 2. Agenda • Datums • GPS - Accuracy • NGS - National Spatial Reference System • MetaData • Tools – DS-World – CORS – OPUS • New Datums
- 3.
- 4. Datums A mathematical andgeometric concept that serves as a foundation or starting point for mapping, surveying, engineering based on realization of actual geospatial data points.
- 5. Geodetic Reference Surfaces A beachball globe Mathematical best fit to Earth’s surface… used for defining Latitude and Longitude Modeled best fit to “sea surface” equipotential gravity field used for defining Elevation
- 6. Geodetic Datums Horizontal 2-D (Latitude and Longitude) (e.g. NAD 27, NAD 83 (1986)) Vertical/Geopotential 1-D (Orthometric Height) (e.g. NGVD 29, NAVD 88, Local Tidal) Geometric 3-D (Latitude, Longitude and Ellipsoid Height) Fixed and Stable(?) - Coordinates seldom change (e.g. NAD 83 (1993), NAD 83 (2007)) also 4-D (Latitude, Longitude, Ellipsoid Height, Velocities) Coordinates change with time (e.g. NAD 83, ITRF00, ITRF05)
- 7. GPS Receiver Grades •Recreational Grade – $100-$1000 1-10 meters • Mapping – $2,000-$6,000 submeter - 3 meter • Survey Grade – $10,000 + 5mm – 2 cm 2010 May 11 Federal Geospatial Summit 14
- 8. Autonomous GPS Accuracy 25hrs @ 1 fix/15 sec = 6,000 fixes Mean Fix: 0.8m @ 212 deg 50% of fixes w/in 1.8m 68% of fixes w/in 2.4m 6.3 meters 5.0 95% of fixes w/in 4.2m 3.8 99% of fixes w/in 5.7m 2.5 1.3 *
- 9. Accuracy Precision
- 10. U.S. Department ofCommerce National Oceanic & Atmospheric Administration National Geodetic Survey Mission: To define, maintain & provide access to the National Spatial Reference System (NSRS) to meet our Nation’s economic, social & environmental needs National Spatial Reference System •Latitude •Scale •Longitude •Gravity •Height •Orientation & their time variations
- 11. The NSRS Supports Nautical charts, among many other geospatial applications National Oceanic and Atmospheric Administration Flood zones for the National Flood Insurance Program Emergency Response Imagery Federal Emergency Management Agency Levee Safety Program to determine levee heights and positions United States Army Corps of Engineers Topographic Maps and interior water data for the nation United States Geological Survey NSRS gravity data for the geospatial mission of NGA National Geospatial-Intelligence Agency Aeronautical Data Quality Assurance Federal Aviation Administration
- 12. The NSRS hasevolved 1 Million 70,000 Monuments Passive Marks (Separate (3-Dimensional) Horizontal and Vertical Systems) Passive Marks 1,800+ CORS (Time Dependent (Limited Knowledge System Possible; of Stability) 4-Dimensional) GPS CORS GNSS CORS
- 13. NGS National Spatial Reference System(NSRS) Improvements TIME NETWORK LOCAL NETWORK SPAN ACCURACY ACCURACY NAD 27 1927-1986 10 meter s (1 part in 100,000) NAD83(86) 1986-1990 1 meter (1 part in 100,000) NAD83(199x)* 1990-2007 0.1 meter B-order (1 part in 1 million) HARN A-order (1 part in 10 million) NAD83(NSRS2007) 2007 - 2011 0.01 meter 0.01 meter (CORS) NAD83(NSRS2007) 2011 - 0.01 meter 0.01 meter (CORS) * CO was completed and adjusted in 1992
- 14. Accurate positioning begins with accurate coordinates Geodetic control (the NSRS) is the foundation for all geospatial products. Without Geodetic Control as a “base map” layer, GIS applications will not work properly Source: Zurich-American Insurance Group
- 15. Same point different datum's= different lat/long’s 1000 m radius COMET 500 m radius Flagpole NAD83
- 16. Datum Differences NAD 27– NAD 83
- 17. Datum Difference NGVD 29– NAVD 88
- 18. -1.18 ft to+1.28 ft
- 20. 2011 US TopoMap Slide by John Kosovich, USGS
- 21. Are NAD 83& WGS 84 The Same? NO but for your application is it significant? If requirements are greater than 3m then Yes If requirements are less than 3m then No Federal Register Notice: Vol. 60, No. 157, August 15, 1995, pg. 42146 “Use of NAD 83/WGS 84 Datum Tag on Mapping Products”
- 22. State Plane Coordinates State plane coordinates are the projection of latitudes and longitudes To a flat mapping surface that is usually defined by state law
- 23. Plane Coordinate ConversionTools State Plane Coordinates GPPCGP (NAD 27 only) SPCS83 (NAD 83 only) http://www.ngs.noaa.gov/TOOLS/spc.shtml UTM UTMS (Both NAD 27 & NAD 83) http://www.ngs.noaa.gov/TOOLS/utm.shtml Both CORPSCON (Both NAD 27 & NAD 83) http://crunch.tec.army.mil/software/corpscon/corpscon.html www.ngs.noaa.gov www.geodesy.noaa.gov
- 24. Height Modernization Height Modernization -faster -cheaper Differential Leveling (Orthometric HT) GNSS (Ellipsoid Ht)
- 25. Ellipsoid, Geoid, and Orthometric Heights H = Orthometric Height (leveling) h = Ellipsoidal Height (GPS) H =h-N N = Geoid Height (model) h (NAD83) TOPOGRAPHIC (NAVD88) H SURFACE N Geoid Height Geoid (GEOID09) Ellipsoid
- 26. Ellipsoid, Geoid, and Orthometric Heights H = Orthometric Height (leveling) h = Ellipsoidal Height (GPS) H =h-N N = Geoid Height (model) h (NAD83) TOPOGRAPHIC (NAVD88) H SURFACE N Geoid Height Geoid (GEOID09) Ellipsoid TRANSPORTATION 1660.6 = 1643.354 – (-17.23*) METERS 1660.6 = 1643.4 + 17.2 *56.53 feet
- 27. Exaggerated view ofthe Earths Gravity Measure
- 28. Gravity for theRedefinition of the American Vertical Datum (GRAV-D) • GRAV-D means fast, accurate, consistent orthometric heights everywhere in the USA • GPS already gives fast accurate ellipsoid heights • If the geoid were modeled (and monitored) to highest accuracy… • Voila… Fast, accurate orthometric heights, anywhere, anytime • No need to use leveling to “bring in the datum”
- 29. Gravity for theRedefinition of the American Vertical Datum (GRAV-D) • Replace the Vertical Datum of the USA by 2022 (at today’s funding) with a gravimetric geoid accurate to 1 cm • Orthometric heights accessed via GNSS accurate to 2 cm • Three components of project: – Airborne gravity survey of entire country and its holdings – Long-term monitoring of geoid change – Partnership surveys Gravity and Heights are inseparably connected
- 30. Building a GravityField Long Wavelengths: (≥ 350 km) GRACE and GOCE (not shown) + Intermediate Wavelengths (500 km to 20 km) Airborne Measurement + Short Wavelengths (< 100 km) Surface Measurement 41
- 31. GRAV-D Update Alaska FY10-13 West Coast FY11 FY10 = Green FY11 = Blue FY12 = Orange FY13 = White Great Lakes FY11-13 FY12 Texas 42 January 23, 2012
- 32. For instance: Whatis the Source of the Data? What is the Datum/Adjustment Epoch? What are the Field Conditions? What Equipment was used, especially what Antenna? What firmware was in the receiver and collector? What redundancy, if any, was used?
- 33. Legislation for NAD83 and units * Utah is now a U.S. Survey Foot State(Blue)
- 34. “DSWorld” Software Program • Highly rated new NGS software tool • Developed to search the NGS database • Easy to learn/use • Multiple search options available • Displays search results using Google Earth
- 35. Geodetic Control Triangles –Horizontal Control Blue – First Order Squares – Vertical Control Red – Second Order
- 36. Triangles – HorizontalControl Black - Third Order
- 37. Datasheets Recovery Photos Directions Descriptions
- 38. Direct Access tothe NGS Datasheet
- 39. 2010 May 11 Federal Geospatial Summit 50
- 40. 2010 May 11 Federal Geospatial Summit 51
- 41.
- 42. Where do youget DS-World?
- 45. OPUS Online Positioning User Service • OPUS – S (2 hrs) • OPUS – RS (15 minutes) • OPUS – DB (Publish) • OPUS – Projects (Network)
- 46. 4,000++ OPUS-Published Solutions April 2012
- 47. NGS Data Sheets Traditional New blue booking OPUS-DB
- 48. OPUS Submission Webpage Your email address Location of your data file Your antenna type Antenna height Customize your solution - details on next slide
- 50. Introducing… NAD 83(2011) epoch 2010.00 • Multi-Year CORS Solution (MYCS) – Reprocessed all CORS GPS data Jan 1994-Apr 2011 – 2264 CORS & global stations – NAD 83 computed by transformation from IGS08 • National Adjustment of 2011 (NA2011) – New adjustment of GNSS passive control – GNSS vectors tied (and constrained) to CORS NAD 83(2011) epoch 2010.00 – Approximately 80,000 stations and more than 400,000 GNSS vectors
- 51. Changes in HorizontalNAD 83 Positions Different Epochs NAD 83(2011) epoch 2010.0 – NAD 83(CORS96) epoch 2002.0 ID+MT+ND+S WA+OR East D+WY 4.4E,5N 1.4E, -0.2N cm 1.7E,0.5N cm cm CA+NV 10.8E, 14.4N cm UT+CO+N M+AZ 0.5E,1.0N cm
- 52. Changes in HorizontalNAD 83 Positions Same Epoch NAD 83(2011) epoch 2002.00 – NAD 83(CORS96) epoch 2002.00
- 53. CONUS Secondary Alaska Pacific (MA11) CONUS Primary Pacific (PA11)
- 56. NAD 83(2011/PA11/MA11) epoch 2010.00 Passive control results summary • Station network accuracies (95% confidence) – Overall median: 0.9 cm horiz, 1.5 cm height • 90% < 2.3 cm horizontal and 4.8 cm ellipsoid height – Median accuracies by network • CONUS Primary: 0.7 cm horiz, 1.2 cm height • CONUS Secondary: 1.6 cm horiz, 3.4 cm height • Alaska: 3.2 cm horiz, 5.7 cm height • Pacific (PA11): 2.2 cm horiz, 5.0 cm height • Pacific (MA11): 1.8 cm horiz, 3.8 cm height
- 57. NAD 83(2011/PA11/MA11) epoch 2010.00 Passive control results summary • Station coordinate and height changes – Overall median: 1.9 cm horiz, 2.1 cm height • 97% changed < 5 cm horizontally and vertically – Median accuracies by network • CONUS : 1.9 cm horiz, 2.1 cm height • Alaska: 6.3 cm horiz, 2.8 cm height • Pacific (PA11): 2.1 cm horiz, 2.3 cm height • Pacific (MA11): 2.5 cm horiz, 6.8 cm height
- 58. National Geodetic Survey Ten+Year Plan • Official NGS policy as of January 2008 • Replace NAVD 88 with a GPS/geoid datum • Replace NAD 83 with a geocentric GPS based datum • New 10 Year Plan for 2013
- 60. New Vertical Datum (Outcome)
- 61. How to Planfor the Future • Use most recent realization of NAD 83 • Move away from passive marks to GNSS • Move off of NGVD 29 to NAVD 88 – Understand the accuracy of VERTCON in your area • Collect OPUS-DB on NAVD 88 bench • Require/provide complete metadata for all survey/mapping contracts – How did they get the positions/heights? – Survey Manual/Spatial Data Accuracy and Georeferencing Standards
- 62. NGS Training Center Webinars! http://www.ngs.noaa.gov/corbin/
- 63. More information… NGS HomePage: http://www.geodesy.noaa.gov geodesy.noaa.gov CORS Webpage: http://www.ngs.noaa.gov/CORS/ CORS newsletter OPUS Webpage: http://www.ngs.noaa.gov/OPUS/ Find Your Advisor: www.ngs.noaa.gov/ADVISORS/AdvisorsIndex.shtml This presentation will be uploaded to: http://www.ngs.noaa.gov/web/science_edu/presentations_archive/ FAQs on the various webpages
- 64.
- 65. 2010 May 11 Federal Geospatial Summit 83
- 66. Questions GOOD COORDINATIONBEGINS WITH GOOD COORDINATES GEOGRAPHY WITHOUT GEODESY IS A FELONY [email protected] 303-202-4082 240-988-6363