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almanac

Parameters for Earth, planets, Sun, and Moon

Syntax

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

Description

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

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

almanac(body) lists the options, or parameters, available for each celestial body. Valid body strings are

'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 strings 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 valid predefined ellipsoid string. In this case, the two-element ellipsoid vector for that ellipsoid model is returned. Valid ellipsoid definition strings 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 strings '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 string. 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 referencebody string of 'actual' returns a tabulated value rather than one dependent upon a ellipsoid model assumption. Other possible referencebody strings 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 strings 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.

More About

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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.

See Also

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