Greenland Geoid 2016
--------------------

This directory contains the Greenland Geoid 2016, based on a large
set of gravity data from satellite, airborne and in-situ measurements,
including recent airborne gravity data from NASA-IceBridge and NASA-OMG.
The geoid has been shifted by -15.6 cm from the global WGS84 computation 
system, to match ASIAQ mean sea level at Nuuk. The geoid definines a new
Greenland Vertical Reference Frame, ready for GPS height determination.
The geoid accuracy is estimated to be 5-10 cm rms over most of the ice-free
region in Greenland. 

The geoid is computed in a 0.02 x 0.05 degree grid, 58-85 N, and 77-7 W. 
The following formats are available:

ggeoid16.gri - native GRAVSOFT format (E-W rows from N to S, with initial header)
ggeoid16.grd - SURFER grid format
ggeoid16.tif - GeoTiff, 32 bit floating
ggeoid16.ggf - Trimble format
ggeoid16.leica - Leica format (one of many), simple ASCII Lat,Lon,Geoid list.

Interpolation program "grid_int_grl.exe" provide an interface to the GRAVSOFT grid

Nov 30, 2016
Rene Forsberg, DTU Space, Denmark
rf@space.dtu.dk

 