edu.nrao.sss.astronomy
Interface CelestialCoordinateConverter

All Known Implementing Classes:

CompositeConverter, EquatorialHorizontalConverter, HeasarcCoordConverter, StarlinkPalConverter

public interface CelestialCoordinateConverter

A converter of sky positions to other celestial coordinate systems.

Version Info:

$Revision: 1132 $

$Date: 2008-02-29 09:29:02 -0700 (Fri, 29 Feb 2008) $

$Author: dharland $

Since:

2007-04-13

Author:

David M. Harland

Method Summary

SkyPosition

createFrom(SkyPosition position, CelestialCoordinateSystem toSystem, Epoch toEpoch, EarthPosition observer, LocalSiderealTime lst) Returns a new position that is equivalent to position, but in the given coordinate system and epoch.

Method Detail

createFrom

SkyPosition createFrom(SkyPosition position,
                       CelestialCoordinateSystem toSystem,
                       Epoch toEpoch,
                       EarthPosition observer,
                       LocalSiderealTime lst)
                       throws CoordinateConversionException

Returns a new position that is equivalent to position, but in the given coordinate system and epoch.

Parameters:

position - the position to be converted.

toSystem - the coordinate system for the returned position.

toEpoch - the epoch for the returned position. Unless the toSystem is EQUATORIAL, this value will probably not be used.

observer - the location of the the observer. Unless one of the coordinate systems is HORIZONTAL, this value will probably not be used.

lst - the local sidereal time at the observer's location. This value is important when one of the coordinate systems is HORIZONTAL. However, it can be used for all systems in order to get the coordinates of position at a particular point in time. If this value is null and neither of the coordinate systems is HORIZONTAL, the coordinates of position will be determined as of the time on the system clock.

Returns:

a new position that is equivalent to position, but is expressed in a coordinate system of toSystem for epoch toEpoch.

Throws:

CoordinateConversionException - if anything goes wrong during conversion.