Presenter: David R. Doyle
Seminar Date: Thursday, October 1, 2020
Seminar Location: Columbia, MD
Sheraton Columbia Town Center Hotel
10207 Wincopin Circle
Columbia, MD 21044
Phone: 410-730-3900
This seminar was originally to take place on May 4 but has been rescheduled due to COVID-19 health and safety regulations.
Seminar location is subject to change.
Registration: 8:00 - 8:30 am
Morning Session: 8:30 am - 12:30 pm
Lunch (On your own): 12:30 - 1:30 pm
Afternoon Session: 1:30 - 5:00 pm
Fundamentals of Geodetic Datums
Horizontal datums
• Geodetic surfaces – ellipsoid and geoid
• Positioning elements of the National Spatial Reference System (NSRS)
• Classical horizontal positioning – triangulation and traverse
• U.S. national horizontal datums – NAD 27 and NAD 83
Development of satellite positioning systems
• Foundation of space-based positioning up to GPS/GNSS
• GPS impact on integrity of NAD 83
• Relationship of NAD 83 and WGS 84
• Horizontal datum transformations – NADCON, Molodensky
Vertical datums
• Vertical datums definitions – geodetic and tidal
• U.S. national vertical datums – NGVD 29 and NAVD 88
• Issues with GPS/GNSS-derived heights
• Vertical datum transformations - VERTCON
New Geodetic Datums for the United States 2022
Rationale for replacing current geodetic datums
• Problems with NAD 83 and NAVD 88
• Introduction to international terrestrial reference frame (ITRF)
• Adoption of ITRF14 into NSRS
National geodetic survey plans for new national datums
• New geometric/geopotential datum definitions
• Gravity for the redefinition of the American vertical datum (GRAV-D)
• Computing approximate horizontal and vertical positional differences
• Importance of positional metadata
Thoughts