org.orekit.frames

Enum LOFType

java.lang.Object

java.lang.Enum<LOFType>

org.orekit.frames.LOFType

All Implemented Interfaces:

Serializable, Comparable<LOFType>

public enum LOFType
extends Enum<LOFType>

Enumerate for different types of Local Orbital Frames.

Author:

Luc Maisonobe

Enum Constant Summary

Enum Constants

Enum Constant and Description
EQW Constant for Equinoctial Coordinate System (X axis aligned with ascending node, Z axis aligned with orbital momentum).
LVLH Constant for Local Vertical, Local Horizontal frame (X axis aligned with position, Z axis aligned with orbital momentum).
LVLH_CCSDS Constant for Local Vertical, Local Horizontal frame as defined by CCSDS (Z axis aligned with opposite of position, Y axis aligned with opposite of orbital momentum).
NTW Constant for Transverse Velocity Normal coordinate system (Y axis aligned with velocity, Z axis aligned with orbital momentum).
QSW Constant for QSW frame (X axis aligned with position, Z axis aligned with orbital momentum).
TNW Constant for TNW frame (X axis aligned with velocity, Z axis aligned with orbital momentum).
VNC Constant for Velocity - Normal - Co-normal frame (X axis aligned with velocity, Y axis aligned with orbital momentum).
VVLH Constant for Vehicle Velocity, Local Horizontal frame (Z axis aligned with opposite of position, Y axis aligned with opposite of orbital momentum).

Method Summary

Modifier and Type	Method and Description
abstract <T extends CalculusFieldElement<T>> FieldRotation<T>	rotationFromInertial(Field<T> field, FieldPVCoordinates<T> pv) Get the rotation from inertial frame to local orbital frame.
abstract Rotation	rotationFromInertial(PVCoordinates pv) Get the rotation from inertial frame to local orbital frame.
static <T extends CalculusFieldElement<T>> FieldRotation<T>	rotationFromLOFInToLOFOut(Field<T> field, LOFType in, LOFType out, FieldPVCoordinates<T> pv) Get the rotation from input to output commonly used local orbital frame.
static Rotation	rotationFromLOFInToLOFOut(LOFType in, LOFType out, PVCoordinates pv) Get the rotation from input to output commonly used local orbital frame.
<T extends CalculusFieldElement<T>> FieldRotation<T>	rotationFromLOFType(Field<T> field, LOFType fromLOF, FieldPVCoordinates<T> pv) Get the rotation from input commonly used local orbital frame to the instance.
Rotation	rotationFromLOFType(LOFType fromLOF, PVCoordinates pv) Get the rotation from input commonly used local orbital frame to the instance.
Transform	transformFromInertial(AbsoluteDate date, PVCoordinates pv) Get the transform from an inertial frame defining position-velocity and the local orbital frame.
<T extends CalculusFieldElement<T>> FieldTransform<T>	transformFromInertial(FieldAbsoluteDate<T> date, FieldPVCoordinates<T> pv) Get the transform from an inertial frame defining position-velocity and the local orbital frame.
static <T extends CalculusFieldElement<T>> FieldTransform<T>	transformFromLOFInToLOFOut(Field<T> field, LOFType in, LOFType out, FieldAbsoluteDate<T> date, FieldPVCoordinates<T> pv) Get the transform from input to output commonly used local orbital frame.
static Transform	transformFromLOFInToLOFOut(LOFType in, LOFType out, AbsoluteDate date, PVCoordinates pv) Get the transform from input to output commonly used local orbital frame.
static LOFType	valueOf(String name) Returns the enum constant of this type with the specified name.
static LOFType[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

TNW

public static final LOFType TNW

Constant for TNW frame (X axis aligned with velocity, Z axis aligned with orbital momentum).

The axes of this frame are parallel to the axes of the VNC and NTW frames:

• X_TNW = X_VNC = Y_NTW
• Y_TNW = -Z_VNC = -X_NTW
• Z_TNW = Y_VNC = Z_NTW

See Also:

VNC, NTW

QSW

public static final LOFType QSW

Constant for QSW frame (X axis aligned with position, Z axis aligned with orbital momentum).

This frame is also known as the LVLH frame, both constants are equivalent.

The axes of these frames are parallel to the axes of the VVLH frame:

• X_QSW/LVLH = -Z_VVLH
• Y_QSW/LVLH = X_VVLH
• Z_QSW/LVLH = -Y_VVLH

See Also:

LVLH, VVLH

LVLH

public static final LOFType LVLH

Constant for Local Vertical, Local Horizontal frame (X axis aligned with position, Z axis aligned with orbital momentum).

BEWARE! Depending on the background (software used, textbook, community), different incompatible definitions for LVLH are used. This one is consistent with Vallado's book and with AGI's STK. However CCSDS standard, Wertz, and a.i. solutions' FreeFlyer use another definition (see LVLH_CCSDS).

This frame is also known as the QSW frame, both constants are equivalent.

The axes of these frames are parallel to the axes of the LVLH_CCSDS frame:

• X_LVLH/QSW = -Z_{LVLH_CCSDS}
• Y_LVLH/QSW = X_{LVLH_CCSDS}
• Z_LVLH/QSW = -Y_{LVLH_CCSDS}

See Also:

QSW, VVLH

LVLH_CCSDS

public static final LOFType LVLH_CCSDS

Constant for Local Vertical, Local Horizontal frame as defined by CCSDS (Z axis aligned with opposite of position, Y axis aligned with opposite of orbital momentum).

BEWARE! Depending on the background (software used, textbook, community), different incompatible definitions for LVLH are used. This one is consistent with CCSDS standard, Wertz, and a.i. solutions' FreeFlyer. However Vallado's book and with AGI's STK use another definition (see LVLH).

The axes of this frame are parallel to the axes of both the QSW and LVLH frames:

• X_{LVLH_CCSDS/VVLH} = Y_QSW/LVLH
• Y_{LVLH_CCSDS/VVLH} = -Z_QSW/LVLH
• Z_{LVLH_CCSDS/VVLH} = -X_QSW/LVLH

Since:

11.0

See Also:

QSW, LVLH

VVLH

public static final LOFType VVLH

Constant for Vehicle Velocity, Local Horizontal frame (Z axis aligned with opposite of position, Y axis aligned with opposite of orbital momentum).

This is another name for LVLH_CCSDS, kept here for compatibility with STK.

Beware that the name is misleading: in the general case (i.e. not perfectly circular), none of the axes is perfectly aligned with velocity! The preferred name for this should be LVLH_CCSDS.

The axes of this frame are parallel to the axes of both the QSW and LVLH frames:

• X_{LVLH_CCSDS/VVLH} = Y_QSW/LVLH
• Y_{LVLH_CCSDS/VVLH} = -Z_QSW/LVLH
• Z_{LVLH_CCSDS/VVLH} = -X_QSW/LVLH

See Also:

LVLH_CCSDS

VNC

public static final LOFType VNC

Constant for Velocity - Normal - Co-normal frame (X axis aligned with velocity, Y axis aligned with orbital momentum).

The axes of this frame are parallel to the axes of the TNW and NTW frames:

• X_VNC = X_TNW = Y_NTW
• Y_VNC = Z_TNW = Z_NTW
• Z_VNC = -Y_TNW = X_NTW

See Also:

TNW, NTW

EQW

public static final LOFType EQW

Constant for Equinoctial Coordinate System (X axis aligned with ascending node, Z axis aligned with orbital momentum).

Since:

11.0

NTW

public static final LOFType NTW

Constant for Transverse Velocity Normal coordinate system (Y axis aligned with velocity, Z axis aligned with orbital momentum).

The axes of this frame are parallel to the axes of the TNW and VNC frames:

• X_NTW = -Y_TNW = Z_VNC
• Y_NTW = X_TNW = X_VNC
• Z_NTW = Z_TNW = Y_VNC

Since:

11.0

See Also:

TNW, VNC

Method Detail

values

public static LOFType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (LOFType c : LOFType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static LOFType valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

rotationFromLOFInToLOFOut

public static Rotation rotationFromLOFInToLOFOut(LOFType in,
                                                 LOFType out,
                                                 PVCoordinates pv)

Get the rotation from input to output commonly used local orbital frame.

This rotation does not include any time derivatives.

Parameters:

in - input commonly used local orbital frame

out - output commonly used local orbital frame

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from input to output commonly used local orbital frame.

Since:

11.3

rotationFromLOFInToLOFOut

public static <T extends CalculusFieldElement<T>> FieldRotation<T> rotationFromLOFInToLOFOut(Field<T> field,
                                                                                             LOFType in,
                                                                                             LOFType out,
                                                                                             FieldPVCoordinates<T> pv)

Get the rotation from input to output commonly used local orbital frame.

This rotation does not include any time derivatives.

Type Parameters:

T - type of the field elements

Parameters:

field - field to which the elements belong

in - input commonly used local orbital frame

out - output commonly used local orbital frame

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from input to output commonly used local orbital frame.

Since:

11.3

transformFromLOFInToLOFOut

public static Transform transformFromLOFInToLOFOut(LOFType in,
                                                   LOFType out,
                                                   AbsoluteDate date,
                                                   PVCoordinates pv)

Get the transform from input to output commonly used local orbital frame.

This method simply builds the transform using the rotation obtained from rotationFromLOFInToLOFOut(LOFType, LOFType, PVCoordinates)

Parameters:

in - input commonly used local orbital frame

out - output commonly used local orbital frame

date - current date

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from input to output commonly used local orbital frame.

Since:

11.3

transformFromLOFInToLOFOut

public static <T extends CalculusFieldElement<T>> FieldTransform<T> transformFromLOFInToLOFOut(Field<T> field,
                                                                                               LOFType in,
                                                                                               LOFType out,
                                                                                               FieldAbsoluteDate<T> date,
                                                                                               FieldPVCoordinates<T> pv)

Get the transform from input to output commonly used local orbital frame.

This method simply builds the transform using the rotation obtained from rotationFromLOFInToLOFOut(LOFType, LOFType, PVCoordinates)

Type Parameters:

T - type of the field elements

Parameters:

field - field to which the elements belong

in - input commonly used local orbital frame

out - output commonly used local orbital frame

date - current date

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from input to output commonly used local orbital frame.

Since:

11.3

rotationFromLOFType

public Rotation rotationFromLOFType(LOFType fromLOF,
                                    PVCoordinates pv)

Get the rotation from input commonly used local orbital frame to the instance.

Parameters:

fromLOF - input local orbital frame

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from input local orbital frame to the instance

Since:

11.3

rotationFromLOFType

public <T extends CalculusFieldElement<T>> FieldRotation<T> rotationFromLOFType(Field<T> field,
                                                                                LOFType fromLOF,
                                                                                FieldPVCoordinates<T> pv)

Get the rotation from input commonly used local orbital frame to the instance.

Type Parameters:

T - type of the field elements

Parameters:

field - field to which the elements belong

fromLOF - input local orbital frame

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from input local orbital frame to the instance

Since:

11.3

transformFromInertial

public Transform transformFromInertial(AbsoluteDate date,
                                       PVCoordinates pv)

Get the transform from an inertial frame defining position-velocity and the local orbital frame.

Parameters:

date - current date

pv - position-velocity of the spacecraft in some inertial frame

Returns:

transform from the frame where position-velocity are defined to local orbital frame

transformFromInertial

public <T extends CalculusFieldElement<T>> FieldTransform<T> transformFromInertial(FieldAbsoluteDate<T> date,
                                                                                   FieldPVCoordinates<T> pv)

Get the transform from an inertial frame defining position-velocity and the local orbital frame.

Type Parameters:

T - type of the fields elements

Parameters:

date - current date

pv - position-velocity of the spacecraft in some inertial frame

Returns:

transform from the frame where position-velocity are defined to local orbital frame

Since:

9.0

rotationFromInertial

public abstract Rotation rotationFromInertial(PVCoordinates pv)

Get the rotation from inertial frame to local orbital frame.

This rotation does not include any time derivatives. If first time derivatives (i.e. rotation rate) is needed as well, the full transformFromInertial method must be called and the complete rotation transform must be extracted from it.

Parameters:

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from inertial frame to local orbital frame

rotationFromInertial

public abstract <T extends CalculusFieldElement<T>> FieldRotation<T> rotationFromInertial(Field<T> field,
                                                                                          FieldPVCoordinates<T> pv)

Get the rotation from inertial frame to local orbital frame.

This rotation does not include any time derivatives. If first time derivatives (i.e. rotation rate) is needed as well, the full transformFromInertial method must be called and the complete rotation transform must be extracted from it.

Type Parameters:

T - type of the field elements

Parameters:

field - field to which the elements belong

pv - position-velocity of the spacecraft in some inertial frame

Returns:

rotation from inertial frame to local orbital frame

Since:

9.0