Interface to the coordinate transform component; J2000 - apparent - local topocentric

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


public interface ITransform
Visual Basic
Public Interface ITransform
Visual C++
public interface class ITransform


Use this component to transform between J2000, apparent and local topocentric (JNow) coordinates or vice versa. To use the component, instantiate it, then use one of SetJ2000 or SetJNow or SetApparent to initialise with known values. Now use the RAJ2000, DECJ200, RAJNow, DECJNow, RAApparent and DECApparent properties to read off the required transformed values.

The component can be reused simply by setting new co-ordinates with a Set command, there is no need to create a new component each time a transform is required.

Transforms are effected through the ASCOM NOVAS-COM engine that encapsulates the USNO NOVAS2 library. The USNO NOVAS reference web page is:

See Also