12
Heights Based on Geopotential Number
•Normal Height (NGVD29) H* = C / g
–g = Average normal gravity along plumb line
•Dynamic Height (IGLD55,85) Hdyn = C / g45
–g45 = Normal gravity at 45° latitude
•Orthometric Height H = C / g
–g = Average gravity along the plumb line
•Helmert Height (NAVD 88) H
= C / (g + 0.0424 H)
–g = Surface gravity measurement (mgals)
