Transform Class

Coordinate transform component; J2000 - apparent - topocentric

Definition

Namespace: ASCOM.Tools
Assembly: ASCOM.AstrometryTools (in ASCOM.AstrometryTools.dll) Version: 2.2.1+77356f79b05b579f6d860a4edd5934fda9fe29e4
C#
public class Transform : IDisposable
Inheritance
Object    Transform
Implements
IDisposable

Remarks

Use this component to transform between J2000, apparent and 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 etc. 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 SOFA component that encapsulates the IAU SOFA library. The IA SOFA reference web page is: https://www.iausofa.org/, which includes links to the SOFA manual and handbook.

Constructors

Transform Create a Transform component without a logger
Transform(ILogger) Create a Transform component with an ILogger logger

Properties

AzimuthObserved Observed azimuth in degrees (topocentric azimuth allowing for refraction)
AzimuthTopocentric Returns the topocentric azimuth angle of the target
DECApparent Returns the Declination in apparent co-ordinates
DecJ2000 Returns the Declination in J2000 co-ordinates
DECObserved Observed declination in degrees (topocentric declination allowing for refraction)
DECTopocentric Returns the Declination in topocentric co-ordinates
DeltaUT1 Set the delta UT1 value to be used by Transform, defaults to 0.0
ElevationObserved Observed elevation in degrees (topocentric elevation allowing for refraction)
ElevationTopocentric Returns the topocentric elevation of the target
JulianDateTT Sets or returns the Julian date on the Terrestrial Time timescale for which the transform will be made
JulianDateUTC Sets or returns the Julian date on the UTC timescale for which the transform will be made
ObservedMode Enables or disables the new "Observed" mode.
RAApparent Returns the Right Ascension in apparent co-ordinates
RAJ2000 Returns the Right Ascension in J2000 co-ordinates
RAObserved Observed RA in hours (topocentric RA allowing for refraction)
RATopocentric Returns the Right Ascension in topocentric co-ordinates
Refraction Gets or sets a flag indicating whether refraction is calculated for topocentric co-ordinates
SiteElevation Gets or sets the site elevation above sea level
SiteLatitude Gets or sets the site latitude
SiteLongitude Gets or sets the site longitude
SitePressure Gets or sets the site atmospheric pressure (not reduced to sea level)
SiteRelativeHumidity Gets or sets the relative humidity at the site in the range 0.0 to 1.0, which correspond to 0% to 100% RH
SiteTemperature Gets or sets the site ambient temperature (not reduced to sea level)

Methods

Dispose Cleans up resources used by the Transform component
Refresh Causes the transform component to recalculate values derived from the last Set command
SetApparent Sets the known apparent Right Ascension and Declination coordinates that are to be transformed
SetAzimuthElevation Sets the topocentric azimuth and elevation
SetAzimuthElevationObserved Sets the observed azimuth and elevation
SetJ2000 Sets the known J2000 Right Ascension and Declination coordinates that are to be transformed
SetObserved Sets the known observed Right Ascension and Declination coordinates that are to be transformed
SetTopocentric Sets the known topocentric Right Ascension and Declination coordinates that are to be transformed

Version Information

.NET Standard

Supported in: 2.0

See Also