This attribute retrieves the values for Keplerian (Classical) elements used to define the spacecraft's Initial State.
Astrogator_RM <Satellite Object Path> GetValue <Astrogator Object Path>.Keplerian.{Attribute}
If you select Keplerian as the Coordinate Type, the following attributes can be specified:
| Attribute | Connect Name |
|---|---|
| ElementType |
|
Size Attributes
| Attribute | Connect Name |
|---|---|
| Element type for Size | SizeType |
| Semi-major Axis | sma |
| Apoapsis Altitude | ApoapsisAltSize |
| Apoapsis Radius | ApoapsisRadSize |
| Mean Motion | MeanMotion |
| Periapsis Altitude | PeriapsisAltSize |
| Periapsis Radius | PeriapsisRadSize |
| Period | Period |
Shape Attributes
| Attribute | Connect Name |
|---|---|
| Element type for Shape | ShapeType |
| Eccentricity | ecc |
| Apoapsis Altitude | ApoapsisAltShape |
| Apoapsis Radius | ApoapsisRadShape |
| Periapsis Altitude | PeriapsisAltShape |
| Periapsis Radius | PeriapsisRadShape |
Node Elements
| Attribute | Connect Name |
|---|---|
| Element type for Node | NodeType |
| Right Asc. of Asc. Node | RAAN |
| Lon. of Asc. Node | LAN |
Anomaly Attributes
| Attribute | Connect Name |
|---|---|
| Element type for Anomaly | AnomType |
| True Anomaly | TA |
| Argument of Latitude | ArgLat |
| Eccentric Anomaly | EccAnomaly |
| Mean Anomaly | MeanAnomaly |
| Time Past Asc. Node | TimePastAN |
| Time Past Periapsis | TimePastPeriapsis |
Other Attributes
| Attribute | Connect Name |
|---|---|
| Inclination | inc |
| Argument of Periapsis | w |
Connect Name is used to set the value of an element while Attribute is used to select the element using an element type attribute.
You can use the SizeType, ShapeType, NodeType, and AnomType attributes to set the element types to use for the size, shape, node, and anomaly elements or you can simply set a value for the desired element type and it will be selected automatically. For example, if Mean Motion is selected as the size element type and you send a command that sets the value for Semi-Major Axis to 7,000 km, the type will be changed to Semi-Major Axis.
For Keplerian element sets, when one element value is changed, the values of other currently selected elements will be held constant, while unselected elements may be changed to satisfy interdependencies between them. For example, if you have Time Past Periapsis selected as the anomaly element and sma selected as the size element, and you change the value of sma from 7,000 km to 8,000 km, the value for TimePastPeriapsis will be held constant because it is the selected element for anomaly. TrueAnomaly, however, will be adjusted to accommodate the new sma value.
Therefore, if you want to ensure that an element's value cannot be changed in response to some other element's value being changed, you should select it as its element type before setting the value of other elements.
Troubleshooting
If you are having trouble with commands for Keplerian elements NACKing, the problem may be with the values that you are trying to pass rather than the syntax. Connect will not allow you to set values that Astrogator's user interface prohibits. For example, you cannot set the ElementType to any of the mean element sets if the value for Eccentricity is greater than 1; in the Astrogator user interface these element sets simply do not appear in the drop-down menu, but in Connect there is nothing to prevent you from trying to set such a value and all that will happen in response is that you will receive a NACK.
Initial State Segment
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Initial_State.InitialState.Keplerian
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Initial_State.InitialState.Keplerian.sma
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Initial_State.FinalState.Keplerian
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Initial_State.FinalState.Keplerian.sma
Maneuver Segment
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Maneuver.InitialState.Keplerian
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Maneuver.InitialState.Keplerian.sma
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Maneuver.FinalState.Keplerian
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Maneuver.FinalState.Keplerian.sma
Hold Segment
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Hold.InitialState.Keplerian
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Hold.InitialState.Keplerian.sma
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Hold.FinalState.Keplerian
Astrogator_RM */Satellite/Satellite1 GetValue MainSequence.SegmentList.Hold.FinalState.Keplerian.sma
STK Programming Interface 11.0.1