geocradius

Convert from geocentric latitude to radius of ellipsoid planet

Syntax

r = geocradius(lambda)
r = geocradius(lambda, model)
r = geocradius(lambda, f, Re)


Description

r = geocradius(lambda) estimates the radius, r, of an ellipsoid planet at a particular geocentric latitude, lambda. lambda is in degrees. r is in meters. The default ellipsoid planet is WGS84.

r = geocradius(lambda, model) is an alternate method for estimating the radius for a specific ellipsoid planet. Currently only 'WGS84' is supported for model.

r = geocradius(lambda, f, Re) is another alternate method for estimating the radius for a custom ellipsoid planet defined by flattening, f, and the equatorial radius, Re, in meters.

Examples

Determine radius at 45 degrees latitude:

r = geocradius(45)


r =

  6.3674e+006

Determine radius at multiple latitudes:

r = geocradius([0 45 90])


r =

  1.0e+006 *

    6.3781    6.3674    6.3568

Determine radius at multiple latitudes, specifying WGS84 ellipsoid model:

r = geocradius([0 45 90], 'WGS84')


r =

  1.0e+006 *

    6.3781    6.3674    6.3568

Determine radius at multiple latitudes, specifying custom ellipsoid model:

f = 1/196.877360;
Re = 3397000;
r = geocradius([0 45 90], f, Re)


r =

  1.0e+006 *

    3.3970    3.3883    3.3797

References

Stevens, B. L., and F. L. Lewis, Aircraft Control and Simulation, John Wiley & Sons, New York, NY, 1992

Zipfel, P. H., and D. E. Penny, Modeling and Simulation of Aerospace Vehicle Dynamics, AIAA Education Series, Reston, VA, 2000