ElementConvert(Variable, Variable, Array) Function

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Description

Converts the orbital state specified by elementArray from the fromSystem element set to the toSystem element set. Assumes the central body is Earth. The order of the elements for each element set are listed below (using the Spacecraft properties):

- CARTESIAN: X, Y, Z, VX, VY, VZ

- KEPLERIAN: A, E, I, RAAN, W, TA

- NONSINGULAR_KEPLERIAN: NonSingularA, NonSingularE1, NonSingularE2, NonSingularE3, NonSingularE4, NonSingularE5

- EQUINOCTIAL: EquinoctialA, EquinoctialH, EquinoctialK, EquinoctialP, EquinoctialQ, EquinoctialLongitude

- BROUWER_MEAN: BL_A, BL_E, BL_I, BL_RAAN, BL_W, BL_MA

- J2_BROUWER_MEAN: BLJ2A, BLJ2E, BLJ2I, BLJ2RAAN, BLJ2W, BLJ2MA

- SPHERICAL: SphericalRadius, RA, DEC, Vi, SphericalAzimuth, VerticalFPA

- SPHERICAL_LATLONG: LatLongRadius, Latitude, Longitude, LatLongVi, LatLongAzimuth, HorizontalFPA

- SGP4: Mean I, Mean RAAN, Mean E, Mean W, Mean MA, Mean MeanMotion

- MODIFIED_EQUINOCTIAL: ModifiedEquinoctialP, ModifiedEquinoctialF, ModifiedEquinoctialG, ModifiedEquinoctialH, ModifiedEquinoctialK, ModifiedEquinoctialL

- SGP4_EQUINOCTIAL: Mean EquinoctialH, Mean EquinoctialK, Mean EquinoctialP, Mean EquinoctialQ, Mean EquinoctialLongitude, Mean EquinoctialMeanMotion

Note, when used to convert an element set into Norad elements this function is not compatible with the SGP4/SDP4 propagator.

Timing Precision Mode

This page describes functionality in nanosecond timing precision mode.

Function Signature

ElementConvert(	Variable fromSystem,
	Variable toSystem,
	Array elementArray)

Arguments

fromSystem

Description:

Element set of input state.

Valid Values:

Value	Label
1	CARTESIAN
2	KEPLERIAN
3	NONSINGULAR_KEPLERIAN
4	EQUINOCTIAL
5	BROUWER_MEAN
6	J2_BROUWER_MEAN
7	SPHERICAL
8	SPHERICAL_LATLONG
9	SGP4
10	MODIFIED_EQUINOCTIAL
11	SGP4 EQUINOCTIAL

toSystem

Description:

Element set of output state.

Valid Values:

Value	Label
1	CARTESIAN
2	KEPLERIAN
3	NONSINGULAR_KEPLERIAN
4	EQUINOCTIAL
5	BROUWER_MEAN
6	J2_BROUWER_MEAN
7	SPHERICAL
8	SPHERICAL_LATLONG
9	SGP4
10	MODIFIED_EQUINOCTIAL
11	SGP4 EQUINOCTIAL

elementArray

Description:

A six-element array containing the orbital state in the input element set.

When converting TO Spherical Lat-Long. or SGP4, the input state is assumed to be referenced to the ICRF. When converting FROM Spherical Lat-Long., the input state is assumed to be in the Earth Fixed coordinate system. When converting FROM SGP4, the input state is assumed to be in the TEME coordinate system.

For all other conversions, the output state will be referenced to the same coordinate system as the input state.

Required Size:

At least 6

Return Value

Type:

Array of number (size = 6)

Returns a six-element array containing the orbital state in the output element set. The output state will be referenced to the same coordinate system as the input state.

Syntax

myArray1 = ElementConvert(myVariable1, myVariable2, myArray2);