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NOVAS2COMTransformCat Method
To transform a star's catalog quantities for a change of epoch and/or equator and equinox.

Namespace: ASCOM.Astrometry.NOVAS
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 6.0.0.0 (6.2.0.2774)
Syntax
public void TransformCat(
	TransformationOption option,
	double date_incat,
	ref CatEntry incat,
	double date_newcat,
	ref byte[] newcat_id,
	ref CatEntry newcat
)

Parameters

option
Type: ASCOM.AstrometryTransformationOption
Transformation option
    = 1 ... change epoch; same equator and equinox
    = 2 ... change equator and equinox; same epoch
    = 3 ... change equator and equinox and epoch
date_incat
Type: SystemDouble
TT Julian date, or year, of input catalog data.
incat
Type: ASCOM.AstrometryCatEntry
An entry from the input catalog
date_newcat
Type: SystemDouble
TT Julian date, or year, of transformed catalog data.
newcat_id
Type: SystemByte
Three-character abbreviated name of the transformed catalog.
newcat
Type: ASCOM.AstrometryCatEntry
OUT: The transformed catalog entry
Remarks
 1. 'date_incat' and 'date_newcat' may be specified either as a 
    Julian date (e.g., 2433282.5) or a Julian year and fraction 
    (e.g., 1950.0).  Values less than 10000 are assumed to be years.
 
 2. option = 1 updates the star's data to account for the star's space motion between 
               the first and second dates, within a fixed reference frame.
    option = 2 applies a rotation of the reference frame corresponding to precession 
               between the first and second dates, but leaves the star fixed in space.
    option = 3 provides both transformations.
 
 3. This subroutine cannot be properly used to bring data from 
    old (pre-FK5) star catalogs into the modern system, because old 
    catalogs were compiled using a set of constants that are 
    incompatible with the IAU (1976) system.
 
 4. This function uses TDB Julian dates internally, but no 
    distinction between TDB and TT is necessary.
See Also