Who am I? National Geodetic Survey s Great Lakes Region Geodetic Advisor. John Ellingson Cell:

Transcription

1 Who am I? National Geodetic Survey s Great Lakes Region Geodetic Advisor John Ellingson john.ellingson@noaa.gov Cell:

2 Today s Discussion 1st Topic New Datums Coming in nd Topic ---- Updated version of Geoid12B 3rd Topic ---- NCAT (Transformation Tool) 4th Topic Free NGS Training/Learning Opportunities Time slot at the end for questions.

3 1 st First Topic ---New Datums Let s start with the GEOPOTENTIAL DATUM (replacing NAVD 88) 4

4 Replacing NAVD 88.Why isn t NAVD 88 NAVD 88 suffers from bench marks that: Are often 80+ years old good enough anymore? Are almost never re-checked for movement Disappear by the thousands every year Are seldom being replaced May not exist near locations where they are needed Were all determined by leveling from a single point, allowing unwanted crosscountry error build up 5

5 Why isn t NAVD 88 good enough anymore? Newer methods to determine/establish heights are available (GNSS), but in many places NAVD 88 doesn t support them very well There are areas where NAVD 88 marks are scarce.or do not exist This example is 100 miles across 6

6 Initial point of NAVD 88. FATHER POINT 7

7 Why replace NAVD 88? BIAS of Approximately ½ meter KNOWN TILT..(about a meter) from SE to NW 8 8

8 GRACE (NASA and Germany) Gravity Recovery and Climate Experiment (launched 2002, decommissioned October 2017) GOCE (European Space Agency) Gravity Field and Steady-State Ocean Circulation Explorer (launched 2009, ended November 2013) 9

9 Gravity for the Redefinition of the American Vertical Datum TRANSITION TO THE FUTURE GRAV-D Goal: Create gravimetric geoid accurate to 1 cm where possible using airborne gravity data Overall Target: 2 cm accuracy orthometric heights from GNSS and a geoid model GRAV-D: Two thrusts of the project Airborne gravity survey of entire country and its holdings Long-term monitoring of geoid change Official NGS policy as of Nov 14,

10 Survey and Block Plans Data lines spaced 10 km apart Cross lines spaced km apart Flight altitude 20,000 ft. Nominal speed knots

11 GRAV-D current status 12

12 GRAV-D status in Michigan 13

13 NGS Gravity Slope Surveys to verify that GRAV-D Works GSVS 2014 GSVS 2017 GSVS

14 GRAV-D will produce the new 2022 GEOPOTENTIAL DATUM known as NAPGD2022 NGS will create a new GEOID Model in 2022 to match (use with) NAPGD2022 Older Geoid Models will NOT work with NAPGD

15 What changes can we expect to see in our orthometric heights? Some approx. delta heights in MICHIGAN

16 Let s move on to the GEOMETRIC (hz) datum (Lat/Lon/El Ht) The North American Terrestrial Reference Frame of 2022 NATRF

17 Why replace NAD 83? NAD 83 was aligned to Geodetic Reference System 1980 (GRS80), and so was the original World Geodetic System 1984 (WGS84) meaning NAD 83 IS equivalent to the original WGS 84.but NOT to the newer versions. Newer versions of WGS 84 have been developed to be consistent with updated International Terrestrial Reference Frames (ITRFXX) G730 (June 1994) G873 (January 1997) G1150 (January 2002) G1674 (February 2012) G1762 (October 2013) 0.7 m 0.2 m 0.06 m 0.01 m 0.01 m 18

18 What is the difference between ITRF 2008 and NAD 83? ITRF 08 19

19 Why a new GEOMETRIC DATUM? The big picture 20

20 How will these new datums impact my work (updated values)? Users in this region will see a GEOMETRIC (3-D) shift of about 1.6 meters (~1.2 m Lat/Lon & ~ 1.1m El. HT) Some users may take years to switch to the new datums! The NGS 10 year plan states that a transformation tool will be provided at the release of the new datums that will enable users to transform values between the older datums (NAD 83 and NAVD 88) and the new GEOMETRIC and GEOPOTENTIAL datums. 21

21 Wrap-up of 1 st Topic New Datums New GEOPOTENTIAL DATUM (vertical) named NAPGD2022 (North American-Pacific Geopotential Datum of 2022) New GEOMETRIC DATUM (hz really 3D) named NATRF2022 (North American Terrestrial Reference Frame of 2022) 22

22 Let s move to Topic #2: Geoid Models (Using your GNSS equipment to determine elevations) 23

23 ELLIPSOID - GEOID RELATIONSHIP H = Orthometric Height (NAVD 88) h = Ellipsoidal Height (NAD 83 (2011)) N = Geoid Height (GEOID12B) H h N Ground Surface Geoid Geoid Ellipsoid GRS80 H ~ h N N is negative in conterminous US 24

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25 GEOID12A estimated accuracy map for MICHIGAN NOTE: GEOID12A & GEOID12B are equivalent in MICHIGAN 26

26 NGS is replacing Geoid12B, the current NAVD 88 geoid model NGS is working with all of our State partners to create one final improvement to the GEOID model for NAVD 88! It will be called GEOID18 Development is going on at this time.. 27

27 LAST NAVD 88 GEOID MODEL - SCHEDULE Oct Initial data pull, work is now underway Jan Deliver prototype to Advisors for review, and dispersed to users for review Mar *Surveyors Week GPSonBM campaign Aug Cut off for Data Submission by partners Oct 2018 Final database extraction for model Dec 2018 Beta product release Jan-Feb 2019 Outreach at Survey Conferences Mar 2019 Integrate new model into NGS products (OPUS, Datasheets, etc). 28

28 Now our 3rd topic: NGS Transformation Tools GEOCON 2.0..then came GEOCON 5.0 Now we have NCAT NGS COORDINATE CONVERSION AND TRANSFORMATION TOOL 29

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30 It started as GEOCON

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32 Remember to account for accuracy! INPUT AND OUTPUT REALIZATIONS. AVAILABLE CHOICES (1994) NOT in MI 33

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34 In early February, NCAT tool was moved from Beta to Production If you experience problems, contact me. If you find a bug please inform me, or NGS.Feedback@noaa.gov 35

35 TOPIC #4 Learning Opportunities Monthly webinar series (plus archived presentations) Presentation Library YouTube Videos Corbin Training Center hands on classroom training OPUS Projects Training 36

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37 NGS Monthly Webinar Series 38

38 NGS Monthly Webinar Series Register For Upcoming Topics Download Past Presentations 39

39 NGS Monthly Webinar Series Examples of past webinars that are available for download 40

40 NGS Presentations Library 41

41 YouTube Videos by NGS 42

42 NGS CORBIN TRAINING CENTER 43

43 OPUS-Projects Class - 2 days- Advisor Instructed 44

44 Odds and Ends (If time permits) NGS Industry Days coming in May 2018 Update on State Plane Coordinate Systems for New Datums OPUS-SHARE: Wait Times before you submit your data to OPUS Ultra-rapid (iguwwwwd.sp3) 6-hour latency Rapid (igrwwwwd.sp3) 13-hour latency Final or Precise (igswwwwd.sp3) 12 to 14 day latency

45 Questions. My contact information: John Ellingson NGS Great Lakes Region Geodetic Advisor Cell: