The Geoid Height block calculates the geoid height using the Geopotential model parameter. The block interpolates the geoid heights from a grid of point values in the tide-free system. It uses the specified geopotential model to degree and order 360. The geoid undulations are relative to the WGS84 ellipsoid.
The interpolation scheme wraps over the poles to allow for geoid height calculations at and near these locations.
Specifies the parameter and output units:
From the list, select the geopotential model.
Default. EGM96 Geopotential Model to degree and order 360. This model uses a 15-minute grid of point values in the tide-free system. This block calculates geoid heights to an accuracy of 0.01 m for this model.
EGM2008 Geopotential Model to degree and order 2159. This model uses a 2.5-minute grid of point values in the tide-free system. This block calculates geoid heights to an accuracy of 0.001 m for this model.
This block requires that you download geoid data for the EGM2008
Geopotential Model with the Add-On Explorer. Click the Get
data button to start the Add-On Explorer. For more information,
Custom geopotential model that you define in Geopotential
mat-file. This block calculates geoid heights to an accuracy
of 0.01 m for custom models. Selecting
Specifies the MAT-file that defines your custom geopotential model. Selecting Geopotential model > Custom enables this parameter.
Specifies the data type of the input and output signals. From
the list, select
Defines action for out-of-range input. Specify one:
|Scalar||Contains geocentric latitude in degrees, where north latitude is positive, and south latitude is negative. Input latitude must be of type single or double. If latitude is not in the range from –90 to 90, the block wraps it to be within the range.|
|Scalar||Contains geocentric longitude in degrees, where east longitude is positive in the range from 0 to 360. Input longitude must be of type single or double. If longitude is not in the range from 0 to 360, the block wraps it to be within the range.|
|Scalar||Contains the geoid height in selected length units. The data type is the same as the latitude in the first input.|
This block has the limitations of the selected geopotential model.
Vallado, D. A. “Fundamentals of Astrodynamics and Applications.” McGraw-Hill, New York, 1997.
NIMA TR8350.2: "Department of Defense World Geodetic System 1984, Its Definition, and Relationship with Local Geodetic Systems."
National Geospatial-Intelligence Agency website: