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TwoLineElementSet Class

A NORAD two-line element set (TLE). Note that the precision of most TLEs is limited by the string representations in the TLE. The resulting ephemeris has a precision on the order of kilometers. When creating a TLE based on orbital elements, it is important to note that information will be lost when converting precise elements into a string representation.
Inheritance Hierarchy

Namespace:  AGI.Foundation.Propagators
Assembly:  AGI.Foundation.Models (in AGI.Foundation.Models.dll) Version: 19.5.402.0 (19.5.402.0)
Syntax
public class TwoLineElementSet : Sgp4Elements

The TwoLineElementSet type exposes the following members.

Constructors
  NameDescription
Public methodTwoLineElementSet
Initializes a new Two Line Element Set with default parameters.
Public methodTwoLineElementSet(String)
Initializes a new Two Line Element Set from a string representation of the TLE. An invalid checksum value will be silently ignored.
Public methodTwoLineElementSet(TwoLineElementSet)
Initializes a new instance as a copy of an existing instance.
Public methodTwoLineElementSet(String, Boolean)
Initializes a new Two Line Element Set from a string representation of the TLE and optionally verifies the checksums.
Public methodTwoLineElementSet(String, Boolean, Char)
Initializes a new Two Line Element Set from a string representation of the TLE and optionally verifies the checksums.
Public methodTwoLineElementSet(Sgp4Elements, String, String, String, String, Double, Double, Int32, Int32)
Initializes a new Two Line Element Set (TLE) from a set of Sgp4Elements and additional meta-data contained in the TLE format.
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Properties
  NameDescription
Public propertyArgumentOfPerigee
Gets or sets the argument of perigee, in degrees.
(Inherited from Sgp4Elements.)
Public propertyBStar
Gets or sets the BSTAR drag term, in units of 1 / EarthRadii. This term represents a modification of the ballistic coefficient (Coefficient of drag times area over mass). The value is modified by one half atmospheric density and expressed in units of inverse Earth radii. Source: https://celestrak.com/
(Inherited from Sgp4Elements.)
Public propertyChecksumLine1
Gets or sets the checksum for line 1.
Public propertyChecksumLine2
Gets or sets the checksum for line 2.
Public propertyClassification
Gets or sets the classification.
Public propertyEccentricity
Gets or sets the eccentricity
(Inherited from Sgp4Elements.)
Public propertyElementNumber
Gets or sets the element number
Public propertyEphemerisType
Gets or sets the ephemeris type. 0=SGP4/SDP4 (as appropriate), 1=SGP, 2=SGP4, 3=SDP4, 4=SGP8, 5=SDP8.
Public propertyEpoch
Gets or sets the epoch at which these initial conditions are defined. Note: The epoch will only be represented to the precision of the TwoLineElementSet format from the RawEpoch. For greater precision, use Sgp4Elements directly.
(Overrides Sgp4ElementsEpoch.)
Public propertyInclination
Gets or sets the inclination, in degrees
(Inherited from Sgp4Elements.)
Public propertyInternationalDesignator
Gets or sets the international designator
Public propertyMeanAnomaly
Gets or sets the mean anomaly, in degrees.
(Inherited from Sgp4Elements.)
Public propertyMeanMotion
Gets or sets the mean motion, in revolutions per day.
(Inherited from Sgp4Elements.)
Public propertyMeanMotionDot
Gets or sets the first derivative of mean motion divided by two, in revolutions per day squared.
Public propertyMeanMotionDotDot
Gets or sets the second derivative of mean motion divided by six, in revolutions per day cubed.
Public propertyName
Gets or sets the spacecraft name
Public propertyRawEpoch
Gets or sets the epoch at which these initial conditions are defined, represented in the standard form: YYDDD.DDDD. Note: this will be represented to only the precision of the TwoLineElementSet format. For greater precision, use Sgp4Elements directly.
(Overrides Sgp4ElementsRawEpoch.)
Public propertyRevolutionNumber
Gets or sets the revolution number at epoch.
Public propertyRightAscensionOfAscendingNode
Gets or sets the right ascension of the ascending node, in degrees
(Inherited from Sgp4Elements.)
Public propertySatelliteNumber
Gets or sets the satellite number.
Public propertySwitchingMethod
Gets or sets the method to use when switching between this element set and the following element set. By default, this is Sgp4ElementsSwitchByEpoch.
(Inherited from Sgp4Elements.)
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Methods
  NameDescription
Public methodClone
Clones this object using the specified context.
(Overrides Sgp4ElementsClone(CopyContext).)
Public methodStatic memberDownloadTles(String, JulianDate, JulianDate)
Downloads TLE data for a given satellite from an Analytical Graphics, Inc. server. Multiple TLEs are returned, spanning the interval provided. This method connects via HTTP to STK11-Online-Ops.agi.com.
Public methodStatic memberDownloadTles(String, JulianDate, JulianDate, IWebProxy)
Downloads TLE data for a given satellite from an Analytical Graphics, Inc. server. Multiple TLEs are returned, spanning the interval provided. This method connects via HTTP to STK11-Online-Ops.agi.com.
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
Public methodToTleString
Returns a TLE string representing this TwoLineElementSet in the standard NORAD format, described by CelesTrak. The format consists of two or three lines with a new line after each. If the Name is not and not empty, the output contains three lines where the first is the result of ToTleStringLine0, the second is the result of ToTleStringLine1, and the third is the result of ToTleStringLine2. If the name is or empty, line zero is omitted. In either case, the lines are separated by your platform's new line string, usually "\n" or "\r\n".
Public methodToTleStringLine0
Returns line 0 of the TLE represented in standard NORAD format, described by CelesTrak. Line 0 contains the Name padded to 24 characters. The returned line does not contain any new line or line break characters.
Public methodToTleStringLine1
Returns line 1 of the TLE represented in standard NORAD format, described by CelesTrak. Line 1 contains the classification, international designator, epoch, etc. The returned line does not contain any new line or line break characters.
Public methodToTleStringLine2
Returns line 2 of the TLE represented in standard NORAD format, described by CelesTrak. Line 2 contains the inclination, right ascension of the ascending node, eccentricity, etc. The returned line does not contain any new line or line break characters.
Public methodStatic memberVerifyChecksum
Verifies the checksum of the specified TLE line.
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Examples
An example of creating a TLE from a string and then initializing an Sgp4Propagator with the TLE:
C#
string tleString =
    "1 20724U 90068A   02173.73395695 -.00000086  00000-0  00000-0 0  1771\n" +
    "2 20724  56.1487  21.0845 0183651 226.6216 131.8780  2.00562381 85500\n";
TwoLineElementSet tle = new TwoLineElementSet(tleString);
Sgp4Propagator propagator = new Sgp4Propagator(tle);
See Also