Apply the current NGS hybrid geoid model in GNSS workflows

Steps

1. Confirm the currently designated NGS hybrid geoid model before starting a project — as of the current NSRS realization, GEOID18 is the operational hybrid model used to convert GNSS ellipsoid heights (NAD 83(2011) epoch 2010.0) to NAVD 88 orthometric heights.
2. Download or configure GEOID18 in your GNSS/data-collector software (via geodesy.noaa.gov/GEOID/GEOID18/ or the built-in geoid model library most receivers/software already ship with) rather than an older model like GEOID12B.
3. Apply the model only to ellipsoid heights that are properly referenced to NAD 83(2011) — using GEOID18 with heights tied to a different realization will introduce systematic vertical error.
4. Validate results against a nearby published NGS benchmark with a known NAVD 88 orthometric height where possible, to catch gross model-application errors before relying on derived elevations.
5. Watch for the transition to GEOID2022 (part of the new NAPGD2022 geopotential datum): NGS has stated GEOID18 will be the last hybrid model published before NAPGD2022 is adopted, so confirm on geodesy.noaa.gov whether GEOID2022 has become official before starting a new project, since it will supersede GEOID18.