Iau2006XysData

new Iau2006XysData(options)

A set of IAU2006 XYS data that is used to evaluate the transformation between the International Celestial Reference Frame (ICRF) and the International Terrestrial Reference Frame (ITRF).
Name Type Description
options Object optional Object with the following properties:
Name Type Default Description
xysFileUrlTemplate String 'Assets/IAU2006_XYS/IAU2006_XYS_{0}.json' optional A template URL for obtaining the XYS data. In the template, `{0}` will be replaced with the file index.
interpolationOrder Number 9 optional The order of interpolation to perform on the XYS data.
sampleZeroJulianEphemerisDate Number 2442396.5 optional The Julian ephemeris date (JED) of the first XYS sample.
stepSizeDays Number 1.0 optional The step size, in days, between successive XYS samples.
samplesPerXysFile Number 1000 optional The number of samples in each XYS file.
totalSamples Number 27426 optional The total number of samples in all XYS files.
Source: Core/Iau2006XysData.js, line 39

Methods

computeXysRadians(dayTT, secondTT, result) → Iau2006XysSample

Computes the XYS values for a given date by interpolating. If the required data is not yet downloaded, this method will return undefined.
Name Type Description
dayTT Number The Julian day number for which to compute the XYS value, expressed in the Terrestrial Time (TT) time standard.
secondTT Number The seconds past noon of the date for which to compute the XYS value, expressed in the Terrestrial Time (TT) time standard.
result Iau2006XysSample optional The instance to which to copy the interpolated result. If this parameter is undefined, a new instance is allocated and returned.
Returns:
The interpolated XYS values, or undefined if the required data for this computation has not yet been downloaded.
See:
Source: Core/Iau2006XysData.js, line 141

preload(startDayTT, startSecondTT, stopDayTT, stopSecondTT) → Promise

Preloads XYS data for a specified date range.
Name Type Description
startDayTT Number The Julian day number of the beginning of the interval to preload, expressed in the Terrestrial Time (TT) time standard.
startSecondTT Number The seconds past noon of the beginning of the interval to preload, expressed in the Terrestrial Time (TT) time standard.
stopDayTT Number The Julian day number of the end of the interval to preload, expressed in the Terrestrial Time (TT) time standard.
stopSecondTT Number The seconds past noon of the end of the interval to preload, expressed in the Terrestrial Time (TT) time standard.
Returns:
A promise that, when resolved, indicates that the requested interval has been preloaded.
Source: Core/Iau2006XysData.js, line 101