NAPGD2022 Data Download

Gridded data associated with the various NAPGD2022 models can be downloaded here in the following formats: GGXF, *.bin, and *.b. Additional information about the regional grid extents, test cases, and reading/analyzing the data are also provided below.

The GGXF file for a given model include all of the individual grids as specified in the tables below. These are provided in NetCDF-4 formatting, which is the carrier for binary encoding in GGXF.

More information about GGXF can be found at the Open Geospatial Consortium (OGC)

Model Grid File GGXF
GEOID2022 GEOID2022.beta_v0.ggxf
DEFLEC2022 DEFLEC2022.beta_v0.ggxf
DEM2022 DEM2022.beta_v0.ggxf
GRAV2022 GRAV2022.beta_v0.ggxf

SGEOID2022

Unit: meters

Region Functional Grid File *.bin *.b
North America Geoid undulation SGEOID2022.NA.N.beta_v0
American Samoa Geoid undulation SGEOID2022.AS.N.beta_v0
Guam & CNMI Geoid undulation SGEOID2022.GC.N.beta_v0
North America Geoid uncertainty SGEOID2022.NA.Nsigma.beta_v0
American Samoa Geoid uncertainty SGEOID2022.AS.Nsigma.beta_v0
Guam & CNMI Geoid uncertainty SGEOID2022.GC.Nsigma.beta_v0
North America Geoid-Quasigeoid Separation SGEOID2022.NA.GQS.beta_v0
American Samoa Geoid-Quasigeoid Separation SGEOID2022.AS.GQS.beta_v0
Guam & CNMI Geoid-Quasigeoid Separation SGEOID2022.GC.GQS.beta_v0

DGEOID2022

Unit: meters / year

Region Functional Grid File *.bin *.b
Global Geoid rate DGEOID2022.GL.Ndot.beta_v0
Global Geoid rate uncertainty DGEOID2022.GL.Ndotsigma.beta_v0

SDEFLEC2022

Unit: arcseconds

Region Functional Grid File *.bin *.b
North America East-west deflection of the vertical (eta) SDEFLEC2022.NA.eta.beta_v0
North America North-south deflection of the vertical (xi) SDEFLEC2022.NA.xi.beta_v0
American Samoa East-west deflection of the vertical (eta) SDEFLEC2022.AS.eta.beta_v0
American Samoa North-south deflection of the vertical (xi) SDEFLEC2022.AS.xi.beta_v0
Guam & CNMI East-west deflection of the vertical (eta) SDEFLEC2022.GC.eta.beta_v0
Guam & CNMI North-south deflection of the vertical (xi) SDEFLEC2022.GC.xi.beta_v0
North America eta uncertainty SDEFLEC2022.NA.etasigma.beta_v0
North America xi uncertainty SDEFLEC2022.NA.xisigma.beta_v0
American Samoa eta uncertainty SDEFLEC2022.AS.etasigma.beta_v0
American Samoa xi uncertainty SDEFLEC2022.AS.xisigma.beta_v0
Guam & CNMI eta uncertainty SDEFLEC2022.GC.etasigma.beta_v0
Guam & CNMI xi uncertainty SDEFLEC2022.GC.xisigma.beta_v0

DDEFLEC2022

Unit: arcseconds / year

Region Functional Grid File *.bin *.b
Global Eta rate DDEFLEC2022.GL.etadot.beta_v0
Global Xi rate DDEFLEC2022.GL.xidot.beta_v0

Unit: milligals

Region Functional Grid File *.bin *.b
North America Refined Bouguer anomaly GRAV2022.NA.RBA.beta_v0
North America Refined Bouguer anomaly uncertainty GRAV2022.NA.RBAsigma.beta_v0
North America Terrain correction GRAV2022.NA.TC.beta_v0
American Samoa Refined Bouguer anomaly GRAV2022.AS.RBA.beta_v0
American Samoa Refined Bouguer anomaly uncertainty GRAV2022.AS.RBAsigma.beta_v0
American Samoa Terrain correction GRAV2022.AS.TC.beta_v0
Guam & CNMI Refined Bouguer anomaly GRAV2022.GC.RBA.beta_v0
Guam & CNMI Refined Bouguer anomaly uncertainty GRAV2022.GC.RBAsigma.beta_v0
Guam & CNMI Terrain correction GRAV2022.GC.TC.beta_v0

Model Spherical harmonic coefficients .gfc
GM2022 GM2022.beta_v0.gfc
(.gfc format definition)

Unit: meters

Region Functional Grid File *.bin *.b
North America Orthometric height DEM2022.NA.H1m.beta_v0
American Samoa Orthometric height DEM2022.AS.H1m.beta_v0
Guam & CNMI Orthometric height DEM2022.GC.H1m.beta_v0

Bounding boxes for the regional grids are defined as follows:

Region Min. Latitude Max. Latitude Min. Longitude Max. Longitude
North America 0.0° 90.0° 170.0° 350.0°
American Samoa -22.0° 0.0° 172.0° 193.0°
Guam & CNMI 5.0° 22.0° 130.0° 170.0°
Global -90.0° 90.0° 0.0° 360.0°

Test cases

A spreadsheet of test evaluations of the component models at selected points has been included so users can verify their correct implementation of these models or answer common questions about the datum. These test points include grid boundaries, major cities, and points of geographic and scientific interest.