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almanac

Parameters for Earth, planets, Sun, and Moon

almanac is not recommended. Use earthRadius, referenceEllipsoid, referenceSphere, or wgs84Ellipsoid instead.

Syntax

almanac
almanac(body)
data = almanac(body,parameter)
data = almanac(body,parameter,units)
data = almanac(parameter,units,referencebody)

Description

almanac displays the names of the celestial objects available in the almanac.

almanac(body) lists the options, or parameters, available for any of the following celestial bodies:

'earth'       'pluto'
'jupiter'     'saturn'
'mars'        'sun'
'mercury'     'uranus'
'moon'        'venus'
'neptune'

data = almanac(body,parameter) returns the value of the requested parameter for the celestial body specified by body.

Valid parameter values are 'radius' for the planetary radius, 'ellipsoid' or 'geoid' for the two-element ellipsoid vector, 'surfarea' for the surface area, and 'volume' for the planetary volume.

For the Earth, parameter can also be any of the following valid predefined ellipsoid values. In this case, the two-element ellipsoid vector for that ellipsoid model is returned. Valid ellipsoid definitions for the Earth are:

'everest'

1830 Everest ellipsoid

'bessel'

1841 Bessel ellipsoid

'airy'

1830 Airy ellipsoid

'clarke66'

1866 Clarke ellipsoid

'clarke80'

1880 Clarke ellipsoid

'international'

1924 International ellipsoid

'krasovsky'

1940 Krasovsky ellipsoid

'wgs60'

1960 World Geodetic System ellipsoid

'iau65'

1965 International Astronomical Union ellipsoid

'wgs66'

1966 World Geodetic System ellipsoid

'iau68'

1968 International Astronomical Union ellipsoid

'wgs72'

1972 World Geodetic System ellipsoid

'grs80'

1980 Geodetic Reference System ellipsoid

'wgs84'

1984 World Geodetic System ellipsoid

For the Earth, the parameter values 'ellipsoid' and 'geoid' are equivalent to'grs80'.

data = almanac(body,parameter,units) specifies the units to be used for the output measurement, where units is any valid distance units. Note that these are linear units, but the result for surface area is in square units, and for volume is in cubic units. The default units are 'kilometers'.

data = almanac(parameter,units,referencebody) specifies the source of the information. This sets the assumptions about the shape of the celestial body used in the calculation of volumes and surface areas. A reference body of 'actual' returns a tabulated value rather than one dependent upon a ellipsoid model assumption. Other possible referencebody s are 'sphere' for a spherical assumption and 'ellipsoid' for the default ellipsoid model. The default reference body is 'sphere'.

For the Earth, any of the preceding predefined ellipsoid definition s can also be entered as a reference body.

For Mercury, Pluto, Venus, the Sun, and the Moon, the eccentricity of the ellipsoid model is zero, that is, the 'ellipsoid' reference body is actually a sphere.

Tips

Take care when using angular arc length units for distance measurements. All planets have a radius of 1 radian, for example, and an area unit of square degrees indicates unit squares, 1 degree of arc length on a side, not 1-degree-by-1-degree quadrangles.

Version History

Introduced before R2006a