Geodetic Toolkit: NAVDGRAD

NAVD 88 Gravity Computations

Use this program to compute NAVD 88 surface gravity as a function of latitude and longitude.

Gravity is computed by the method used to compute gravity for the NAVD 88 adjustment.
This is also the method used to compute the Modelled Gravity which shows on NGS data sheets.
Computations may be performed for a specific geographical location or for a file of input points.

The NAVD 88 gravity may differ from the measured gravity at a point,
or from the gravity value produced by the Surface Gravity tool in this toolkit by a few milligals.
This is because:

• The interpolation method used in computing NAVD 88 gravity may introduce some smoothing of measured values.
• NAVD 88 gravity is computed using a gravity model determined at the time of the NAVD 88 adjustment.
  New or revised values added to the NGS gravity data base since that time may affect the Surface Gravity computations
  but will have no effect on the NAVD 88 gravity.

Compute NAVD 88 gravity for a specific location: