10
Text Box: Equipotential Surfaces
Equipotential Surfaces
HC
HA
Text Box: Reference Surface (Geoid)
Reference Surface (Geoid)
DHAC  ¹ DhAB + DhBC 
Observed difference in orthometric height, DH, depends on the leveling route.
A
C
B
Topography
D hAB
D h = local leveled differences
Leveled Height vs. Orthometric Height
= D hBC
DH = relative orthometric heights