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(
lists the options, or parameters, available for any of the following celestial
bodies:body
)
'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:
| 1830 Everest ellipsoid |
| 1841 Bessel ellipsoid |
| 1830 Airy ellipsoid |
| 1866 Clarke ellipsoid |
| 1880 Clarke ellipsoid |
| 1924 International ellipsoid |
| 1940 Krasovsky ellipsoid |
| 1960 World Geodetic System ellipsoid |
' | 1965 International Astronomical Union ellipsoid |
| 1966 World Geodetic System ellipsoid |
| 1968 International Astronomical Union ellipsoid |
| 1972 World Geodetic System ellipsoid |
| 1980 Geodetic Reference System ellipsoid |
| 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
See Also
distance
| earthRadius
| referenceEllipsoid
| referenceSphere
| wgs84Ellipsoid