1. 1 NGA Mission - Data – Collaboration 2009 Workshop on Monitoring North American Geoid Change 21 Oct 2009 NGA Mission - Data – Collaboration 2009 Workshop on Monitoring North American Geoid Change 21 Oct 2009 UNCLASSIFIED James Friederich 314.676.0870 james.e.friederich@nga.mil James Friederich 314.676.0870 james.e.friederich@nga.mil UINCLASSIFIED

2. 2 Overview Earth Gravitational Model 2008 Digital Bathymetry and Elevation Data World Magnetic Model Collaboration on Geoid UNCLASSIFIED

3. 3 Earth Gravitational Model 2008 UNCLASSIFIED UINCLASSIFIED

4. 4 5  5  g Data Sources (v010808) UNCLASSIFIED

5. 5 5  5  g Data Standard Deviations (v010808) UNCLASSIFIED

6. 6 Statistics of 5  5  g (mGal) (v010808) Statistics refer to edited and downward continued gravity anomalies. The area void of high quality 5´ data (~16% of the globe) is also the “roughest” area of the gravity anomaly field. Source % Area Min. Max. RMS RMS  ArcGP3.0-192.0281.830.23.0 Altimetry63.2-361.8351.128.43.0 Terrestrial17.6-351.9868.441.22.8 Fill-in16.2-333.0593.546.87.6 Non Fill-in83.8-361.8868.431.62.9 All100.0-361.8868.434.54.1 ( , ) 19.4°, 293.5°10.8°, 286.3° UNCLASSIFIED

7. 7 The Development of EGM2008 ITG-GRACE03S (Torsten Mayer-Gürr, 2007), along with its complete error covariance matrix to Nmax=180, was used. Least-Squares Adjustment, in terms of Ellipsoidal Harmonic coefficients, was used in order to combine the GRACE-only information with the coefficients implied solely by the terrestrial data. Evaluation, considering residual 5  5  g, GPS/Leveling, Astronomic Deflections of the Vertical, TOPEX Altimetry, the MIT ECCO DOT output, and GRACE KBRR data, was performed. Error Calibration, to optimize data combination and produce realistic propagated errors for various functionals, up to Nmax=2159, with geographic specificity (see Pavlis and Saleh, 2004), was performed. EGM2008 does NOT incorporate any GPS/Leveling or Astronomic Deflections of the Vertical data. UNCLASSIFIED

8. 8 Spectra Related to the EGM2008 Model UNCLASSIFIED

9. 9 EGM2008 Geoid Height UNCLASSIFIED

10. 10 AbsVal of EGM2008 – EGM96 UNCLASSIFIED

11. 11 5  5 Residual  g (Nmax=180) UNCLASSIFIED

12. 12 EGM2008 5  5  Commission Error (Nmax=2159) UNCLASSIFIED

13. 13 EGM2008 5  5  Commission Error (Nmax=2159) UNCLASSIFIED

14. 14 EGM2008 5  5  Commission Error (Nmax=2159) UNCLASSIFIED

15. 15 Region RMS σ N (cm) RMS σ ξ (arcsec) RMS σ η (arcsec) | φ | <66° and Ocean 5.8 (5.2)0.38 (~0.30)0.39 (~0.30) CONUS 5.9 (4.8)0.47 (1.12)0.47 (1.16) Land18.3 (~10.3)1.69 Ocean6.10.42 Globe11.10.98 EGM2008 Commission Error Estimates (Nmax=2159) Parenthetical values represent observed performance based on comparisons with independent data. However, the comparison results include also the omission error of the model. UNCLASSIFIED

16. 16 Summary and Model Availability EGM2008 has been developed and is freely available – http://earth-info.nima.mil/GandG/wgs84/gravitymod/egm2008/egm08_wgs84.html http://earth-info.nima.mil/GandG/wgs84/gravitymod/egm2008/egm08_wgs84.html Overall, EGM2008 maintains or improves upon the performance of EGM96 for terrestrial applications (geoid undulations, deflections of the vertical, DOT, etc.). EGM2008 drastically improves upon the performance of EGM96 for various satellite applications (mostly GRACE- related) UNCLASSIFIED

17. 17 Digital Bathymetry and Elevation Data UNCLASSIFIED UINCLASSIFIED

18. 18 Digital Bathymetry and Elevation Data (DBED) A point prediction of global bathymetry and elevation data based on DTED 0 format Major Bathymetry Source Data –NGA Open Source Bathymetry Database –Danish National Space Center Sea Surface Altimetry –Smith and Sandwell Sea Surface Altimetry Major Elevation Source Data – SRTM, DTED, USGS-GTOPO30, Australia DEM, Danish National Space Center Greenland DEM UNCLASSIFIED

19. 19 Digital Bathymetry and Elevation Data (DBED) SRTM2f Antarctic DEM Greenland DEM Various data Unclassified elevation data sources UNCLASSIFIED

20. 20 Digital Bathymetry and Elevation Data (DBED) United States National Geophysical Data Center US Geologic Survey Lamont-Doherty Earth Observatory Scripps Research Institute Japan Japan Oceanographic Data Center Japan Agency for Marine-Earth Science and Technology Australia Dept of Environment and Water Resources Geoscience Australia United Kingdom British Geological Survey Natural Environment Research Council Germany Institute for Oceanography Alfred Wegener Institute for Polar and Marine Research International Organizations PANGAEA UN – Oceans and Law of the Sea International Bathymetric Chart of the Arctic Ocean International Bathymetric Chart of the Southern Ocean Unclassified Open Source Bathymetry Contributions - partial list UNCLASSIFIED

21. 21 NGA Open Source Bathymetry Holdings January 2009 – 1.4 billion points from ship tracks and DEMs IBCAO DEM Australia DEM Ship Tracks White Areas – Data Voids UNCLASSIFIED

22. 22 Digital Bathymetry and Elevation Data (DBED) 64,800 one-degree cells of seamless elevation and bathymetry data in DTED0 format UNCLASSIFIED

23. 23 DBED 1 Degree Cell Accuracy Estimates UNCLASSIFIED

24. 24 DBED Way Forward Future annual releases –include more/new Open Source bathymetry data –improved bathymetry prediction algorithms from Sea Surface Altimetry data Littoral Geotechnical bathymetry prediction Littoral Tide Model prediction Web Service to select specific areas Public Release version UNCLASSIFIED

25. 25 World Magnetic Model UNCLASSIFIED UINCLASSIFIED

26. 26 NGA / DOD World Magnetic Model Produced by the National Geophysical Data Center (NGDC) and the British Geological Survey (BGS) The release of the WMM-2010 will be available on 15 December, 2009. The file format remains the same as the current wmm.cof fil http://www.ngdc.noaa.gov/geomag/WMM/DoDWMM.shtml WMM-2005 UNCLASSIFIED

27. 27 NGA / NGDC Enhanced Magnetic Model A new Enhanced Magnetic Model for improved navigation will also be available –new data file, new algorithm NGDC-720 model UNCLASSIFIED

28. 28 Collaboration on Geoid UNCLASSIFIED UINCLASSIFIED

29. 29 NGA Mission NGA main mission is to support the US Department of Defense, Intelligence Community, and Commonwealth Partners Collection, processing, evaluation of gravity data sets Maintaining and improving global geoid models UNCLASSIFIED

30. 30 Areas of Collaboration Funding – Monies to support External Projects & Research and Travel are tight; always seeking collaborative efforts Equipment – NGA has absolute and relative gravimeters that could be available for loan Reference Base Stations – various reports, sketches, descriptions, data values available Personnel – limited availability beyond NGA mission UNCLASSIFIED

31. 31 Areas of Collaboration NGA’s Releasable Unclassified Data – including gravity anomaly/point data, elevation data sets, geoids Relative Gravity Software – NGA has provided Gravnet software and training; improvements, upgrades possible Data Center – limited capability (beyond core mission) to process, evaluate, database survey data and information UNCLASSIFIED

32. 32 www.nga.mil UNCLASSIFIED James Friederich 314.676.0870 james.e.friederich@nga.mil James Friederich 314.676.0870 james.e.friederich@nga.mil