Initialize the VelocityVector from a Site object and Greenwich Apparent Sdereal Time.

Namespace: ASCOM.Astrometry.NOVASCOM
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: (


bool SetFromSite(
	Site site,
	double gast
Visual Basic
Function SetFromSite ( _
	site As Site, _
	gast As Double _
) As Boolean
Visual C++
bool SetFromSite(
	Site^ site, 
	double gast


Type: ASCOM.Astrometry.NOVASCOM..::..Site
The Site object from which to initialize
Type: System..::..Double
Greenwich Apparent Sidereal Time

Return Value

True if OK or throws an exception


The velocity vector is that of the observer with respect to the Earth's center of mass. The GAST parameter must be for Greenwich, not local. The time is rotated through the site longitude. See SetFromSiteJD() for an equivalent method that takes UTC Julian Date and optionally Delta-T (eliminating the need for calculating hyper-accurate GAST yourself).

See Also