The National Geodetic Survey has released updated models for transforming heights between ellipsoidal coordinates and physical height systems that relate to water flow. These models cover regions including the conterminous United States (CONUS), Alaska, Hawaii, Puerto Rico, the Virgin Islands, Guam and the Commonwealth of the Northern Mariana Islands, and American Samoa. GEOID12B transforms to NAVD 88 in CONUS and Alaska and to the respective datums for all the other regions (each having its own datum point). Models for the Deflection of the Vertical have also been released for these same regions mainly for aid in navigation systems.
Latest models
Hybrid Geoids
Converts heights from NAD 83 to regional Vertical datums(e.g., NAVD 88)
- GEOID12B
- GEOID12A (replaced by GEOID12B)
- GEOID12 (replaced by GEOID12A)
- GEOID09
- GEOID03
- GEOID06
- GEOID99
- GEOID96
Gravimetric Geoids
Converts heights from ITRFxx to the NGS geoid surface(not NAVD 88 or other Vertical datums)
Hybrid Vertical Deflection Models
- DEFLEC12B based on the 2012 hybrid model
- DEFLEC12A based on the 2012 hybrid model
- DEFLEC09 based on the 2009 hybrid model
- DEFLEC99
- DEFLEC96
Gravimetric Vertical Deflection Models
- USDOV2012 based on the 2012 gravimetric model
- USDOV2009 based on the 2009 gravimetric model
- DMEX97
- DCAR97
- DEFLEC93 / DALASKA94
- DEFLEC90
Geoid Frequently Asked Questions
- What is the geoid? (Definition, History)
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What is a deflection of the vertical?
in process
Models
- What geoid and deflection models has NGS made?
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Comparison of geoid models
in process
- Links to Other Geoid Researchers
- Links to Geoid Research Projects
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The North American Geoid
International Association of Geodesy Commission Project 2.2 -
Who uses the geoid? Studies with NGS geoid models
NGS Research and Projects
- What is GRAV-D?
- NGS Geoid Publications Page
- NGS Geoid Research page
- NGS Geoid Research software
- NGS online presentations
Definitions
