“true” geoid
NAVD 88 datum
Internal vs. Absolute Model Accuracy
A geoid model should predict the surface between two known points (blue) and the unknown point (green)
GEOID03 permits that at 1 cm accuracy to the NAVD 88 datum
However, the absolute accuracy of NAVD 88 datum is unknown WRT to the “true” geoid and MSL
Need to study the relationship between gravimetric geoid, MSL, and NAVD 88 at TBM‘s