geoidegm96

Calculate geoid height as determined from EGM96 Geopotential Model

    Note:   geoidegm96 will be removed in a future version. Use geoidheight instead.

Syntax

N = geoidegm96(lat, long)
N = geoidegm96(lat, long, action)

Description

N = geoidegm96(lat, long) calculates the geoid height as determined from the EGM96 Geopotential Model. It calculates geoid heights to 0.01 meters. This function interpolates geoid heights from a 15-minute grid of point values in the tide-free system, using the EGM96 Geopotential Model to the degree and order 360. The geoid undulations are relative to the WGS84 ellipsoid.

N = geoidegm96(lat, long, action) calculates the geoid height as determined from the EGM96 Geopotential Model. This function performs action if latitude or longitude are out of range.

Inputs required by geoidegm96:

latAn array of m geocentric latitudes, in degrees, where north latitude is positive and south latitude is negative. lat must be of type single or double. If lat is not within the range -90 to 90, inclusive, this function wraps the value to be within the range.
longAn array of m geocentric longitudes, in degrees, where east longitude is positive and west longitude is negative. long must be of type single or double. If long is not within the range 0 to 360 inclusive, this function wraps the value to be within the range.
actionA string to determine action for out-of-range input. Specify if out-of-range input invokes a 'Warning', 'Error', or no action ('None'). The default is 'Warning'.

Examples

Calculate the geoid height at 42.4 degrees N latitude and 71.0 degrees E longitude.

N = geoidegm96( 42.4, 71.0)

Calculate the geoid height at two different locations, with out-of-range actions generating warnings.

N = geoidegm96( [39.3,33.4], [-77.2, 36.5])

Calculate the geoid height with latitude wrapping, with out-of-range actions displaying no warnings.

N = geoidegm96(100,150,'None')

Limitations

This function has the limitations of the 1996 Earth Geopotential Model. For more information, see http://earth-info.nga.mil/GandG/wgs84/gravitymod/egm96/egm96.html.

The WGS84 EGM96 geoid undulations have an error range of +/-0.5 to +/-1.0 meters worldwide.

References

NIMA TR8350.2: "Department of Defense World Geodetic System 1984, Its Definition and Relationship with Local Geodetic Systems."

NASA/TP-1998-206861: "The Development of the Joint NASA GSFC and NIMA Geopotential Model EGM96"

National Geospatial-Intelligence Agency Website: http://earth-info.nga.mil/GandG/wgs84/gravitymod/egm96/egm96.html

See Also

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