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EarthOrientationParameters

EarthOrientationParameters

new

Specifies Earth polar motion coordinates and the difference between UT1 and UTC. These Earth Orientation Parameters (EOP) are primarily used in the transformation from the International Celestial Reference Frame (ITRF) to the International Terrestrial Reference Frame (ITRF).

Parameters:
Name Type Argument Default Description
description.url String <optional>
 The URL from which to obtain EOP data. If neither this parameter nor description.data is specified, all EOP values are assumed to be 0.0. If description.data is specified, this parameter is ignored.
description.data Object <optional>
 The actual EOP data. If neither this parameter nor description.data is specified, all EOP values are assumed to be 0.0.
description.addNewLeapSeconds Boolean <optional>
 true True if leap seconds that are specified in the EOP data but not in LeapSecond#getLeapSeconds should be added to LeapSecond#getLeapSeconds. False if new leap seconds should be handled correctly in the context of the EOP data but otherwise ignored.
Examples
// An example EOP data file, EOP.json:
{
  "columnNames" : ["dateIso8601","xPoleWanderRadians","yPoleWanderRadians","ut1MinusUtcSeconds","lengthOfDayCorrectionSeconds","xCelestialPoleOffsetRadians","yCelestialPoleOffsetRadians","taiMinusUtcSeconds"],
  "samples" : [
     "2011-07-01T00:00:00Z",2.117957047295119e-7,2.111518721609984e-6,-0.2908948,-2.956e-4,3.393695767766752e-11,3.3452143996557983e-10,34.0,
     "2011-07-02T00:00:00Z",2.193297093339541e-7,2.115460256837405e-6,-0.29065,-1.824e-4,-8.241832578862112e-11,5.623838700870617e-10,34.0,
     "2011-07-03T00:00:00Z",2.262286080161428e-7,2.1191157519929706e-6,-0.2905572,1.9e-6,-3.490658503988659e-10,6.981317007977318e-10,34.0
  ]
}
// Loading the EOP data
var eop = new EarthOrientationParameters({ url : 'Data/EOP.json' });
Transforms.earthOrientationParameters = eop;
Source:

Members

<static>

A default EarthOrientationParameters instance that returns zero for all EOP values.

Methods

Computes the Earth Orientation Parameters (EOP) for a given date by interpolating. If the EOP data has not yet been download, this method returns undefined.

Parameters:
Name Type Argument Description
date JulianDate The date for each to evaluate the EOP.
result EarthOrientationParametersSample <optional>
 The instance to which to copy the result. If this parameter is undefined, a new instance is created and returned.
Throws:
RuntimeError : The loaded EOP data has an error and cannot be used.
Returns:
EarthOrientationParametersSample The EOP evaluated at the given date, or undefined if the data necessary to evaluate EOP at the date has not yet been downloaded.
See:

Gets a promise that, when resolved, indicates that the EOP data has been loaded and is ready to use.

Returns:
Promise The promise.
See:
  • when