EarthOrientationParameters

new Cesium.EarthOrientationParameters(options)
engine/Source/Core/EarthOrientationParameters.js 35

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 (ICRF) to the International Terrestrial Reference Frame (ITRF). This object is normally not instantiated directly, use EarthOrientationParameters.fromUrl.
Name Type Description
options object optional Object with the following properties:
Name Type Default Description
data object optional The actual EOP data. If neither this parameter nor options.data is specified, all EOP values are assumed to be 0.0.
addNewLeapSeconds boolean true optional True if leap seconds that are specified in the EOP data but not in JulianDate.leapSeconds should be added to JulianDate.leapSeconds. False if new leap seconds should be handled correctly in the context of the EOP data but otherwise ignored.

Members

static Cesium.EarthOrientationParameters.NONE
engine/Source/Core/EarthOrientationParameters.js 149

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

Methods

static Cesium.EarthOrientationParameters.fromUrl(url, options)
engine/Source/Core/EarthOrientationParameters.js 121

Name Type Description
url Resource | string optional The URL from which to obtain EOP data. If neither this parameter nor options.data is specified, all EOP values are assumed to be 0.0. If options.data is specified, this parameter is ignored.
options object optional Object with the following properties:
Name Type Default Description
addNewLeapSeconds boolean true optional True if leap seconds that are specified in the EOP data but not in JulianDate.leapSeconds should be added to JulianDate.leapSeconds. 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","modifiedJulianDateUtc","xPoleWanderRadians","yPoleWanderRadians","ut1MinusUtcSeconds","lengthOfDayCorrectionSeconds","xCelestialPoleOffsetRadians","yCelestialPoleOffsetRadians","taiMinusUtcSeconds"],
  "samples" : [
     "2011-07-01T00:00:00Z",55743.0,2.117957047295119e-7,2.111518721609984e-6,-0.2908948,-2.956e-4,3.393695767766752e-11,3.3452143996557983e-10,34.0,
     "2011-07-02T00:00:00Z",55744.0,2.193297093339541e-7,2.115460256837405e-6,-0.29065,-1.824e-4,-8.241832578862112e-11,5.623838700870617e-10,34.0,
     "2011-07-03T00:00:00Z",55745.0,2.262286080161428e-7,2.1191157519929706e-6,-0.2905572,1.9e-6,-3.490658503988659e-10,6.981317007977318e-10,34.0
  ]
}
// Loading the EOP data
const eop = await Cesium.EarthOrientationParameters.fromUrl('Data/EOP.json');
Cesium.Transforms.earthOrientationParameters = eop;

compute(date, result) → EarthOrientationParametersSample
engine/Source/Core/EarthOrientationParameters.js 179

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.
Name Type 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.
Returns:
The EOP evaluated at the given date, or undefined if the data necessary to evaluate EOP at the date has not yet been downloaded.
Throws:
  • RuntimeError : The loaded EOP data has an error and cannot be used.
See:
  • EarthOrientationParameters#fromUrl
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