.help skequatorial Mar00 Skywcs
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NAME
skequatorial -- apply pm and transform between equatorial coordinate systems
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SYNOPSIS
call sk_equatorial (incoo, outcoo, ilng, ilat, ipmlng, ipmlat, px, rv,
	            olng, olat)

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pointer	incoo		# the input sky coordinate descriptor
pointer	outcoo		# the output sky coordinate descriptor
double ilng, ilat	# the input sky coordinates in radians
double ipmlng, ipmlat	# the input proper motions in radians  / year
double	px		# the input parallax in arcsec
double	rv		# the input radial velocity in km / sec (+ve receding)
double olng, olat	# the output sky coordinates in radians
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ARGUMENTS
.ls  incoo    
The input sky coordinate descriptor.
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.ls  outcoo    
The output sky coordinate descriptor.
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.ls ilng, ilat
The input sky coordinates in radians.
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.ls ipmlng, ipmlat
The input proper motions. If proper motions are unknown do not set ipmlng
and ipmlat to 0.0, use sk_ultran instead. Note that the ra proper motion
is in dra  not cos (dec) * dra units.
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.ls px
The parallax in arcseconds. Use 0.0 if the proper motion is unknown unknown. 
The parallax value is used only if proper motions are defined.
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.ls rv
The radial velocity in km / sec. Use 0.0 if the radial velocity is unknown.
The radial velocity value is used only if proper motions are defined.
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.ls olng, olat
The output sky coordinates in radians.
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DESCRIPTION
The coordinates in the input sky coordinate system are converted to 
coordinates in the output sky coordinate system.
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NOTES
If the proper motions are undefined use the routine sk_ultran. Zero valued
proper motions are not the same as undefined proper motions.

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SEE ALSO
sk_lltran, sk_ultran
.endhelp