Saving changes...



GNSS Derived Heights 2 – Using the NGS Hybrid Geoid Model & Height Modernization Procedures

GNSS Derived Heights 2 – Using the NGS Hybrid Geoid Model & Height Modernization Procedures

GNSS Derived Heights 2 – Using the NGS Hybrid Geoid Model & Height Modernization Procedures

William Henning Prof LS
William Henning Prof LS
on behalf of GeoLearn LLC

$49.00 $ 49.00 $ 49.00

$49.00 $ 49.00 $ 49.00

$ 49.00 49.00 49.00
49.00 $ 49.00 49.00 49.00
Normal Price: $49.00 $49.00


Launch date: 15 May 2014
Expiry Date:

Last updated: 29 Dec 2020

Reference: 119369

TIming: null

Maximum Attendees:

Places Left: 0

This course is no longer available

Exam is embedded in the course
No preview available
No Exam Available

Latest User Comments

I would like to...

Course Availability

This course is only available to trainees 365 days after purchase. It would need to be repurchased by the trainee if not completed in the allotted time period. This course is no longer available. You will need to repurchase if you wish to take the course again.

You have 365 days left.


Geospatial practitioners understand that geodetic leveling procedures are the most accurate means to propagate NAVD 88 orthometric heights. However, the time, effort, resources and specifications to produce publishable 1st or 2nd order vertical heights on bench marks are too onerous a task for most to take on in an economical fashion. Fortunately, NGS Height Modernization techniques allow for users to obtain orthometric heights at usable accuracies for most project work. This session will describe the NGS height modernization program and the important elements of which it is comprised – such as the hybrid geoid model used with GPS derived NAD 83 ellipsoid heights, establishing site control for flood certificate work, and the relationship of local mean sea level to our vertical datums. Additionally, the new vertical geopotential datum, to be released around 2022, will be explained.


Upon completion of this course, the student will be exposed to:
• Heights from the NGS data sheet
• Height modernization intro
• Water levels and establishing site elevations for flood certifications
• Comparing HTMOD to geodetic leveling
• What is a geoidal surface? What is the geoid?
• Hybrid and gravimetric geoids
• The new vertical datum in 2022
• GNSS derived height formula: from GNSS NAD 83 ellipsoid heights to NAVD 88 orthometric heights using the NGS hybrid geoid model
William Henning Prof LS

Author Information Play Video Bio

William Henning Prof LS
on behalf of GeoLearn LLC

William Henning is a Registered Professional Land Surveyor with over 45 years of active experience in all phases of the land surveying profession. He has been actively involved with education/outreach to the geospatial community for almost 20 years, presenting over 100 talks and workshops on surveying and GNSS technology. Mr. Henning has authored articles for professional journals and trade magazines on GNSS positioning as well as authoring an extensive guideline document on single base real-time GNSS positioning and editing a real-time network guideline document while working at NOAA’s National Geodetic Survey (NGS). He has been the project lead for new height modernization geodetic networks in county-wide projects in the U.S., where he planned, helped construct, processed, adjusted and managed new geodetic control systems. Mr. Henning is Past President of the American Association for Geodetic Surveying (AAGS) and is an ACSM/AAGS Fellow. He has been presented with the NOAA Administrator’s Award for outstanding accomplishment in producing real time GNSS guidelines. He was awarded the Maryland Society of Surveyors “Surveyor of the Year” for 2013-14.

Current Accreditations

This course has been certified by or provided by the following Certified Organization/s:

  • Texas A&M University Corpus Christi
  • 1.00 Hours

Faculty and Disclosures

Additional Contributors

Conflicts Declared

Conflicts of Interest declaration by Author:


User Reviews (0)

Go Back


Saving changes...