Plate Object

The Plate object can be used to create a model that represents the geometry of a Spacecraft to be used for higher fidelity Solar Radiation Pressure (SRP) modeling. Users can define the size and orientation of plates with respect to the Spacecraft Body Coordinate System, configure plates to track the Sun in either single-axis or two-axis rotation, and query the SRP force and torque generated by the PlateModel. See the Flat Plate Model guide for more information.

Users cannot create instances of this type of object. However, users can access instances of this object type that have been created indirectly, for example as children of other objects. Users can also access any static properties and methods on this object type.

Available In Editions:

Timing Precision Mode

This page describes functionality in millisecond timing precision mode. Millisecond timing precision mode is deprecated and will be removed in a future release. We recommend that you migrate your Mission Plans to nanosecond timing precision mode.

Name	Description	Attributes
Absorption	The coefficient of absorption of this plate. This is computed as Absorption = 1 - (DiffuseReflectivity + SpecularReflectivity).	Type: Variable Access: Read-Only
ActiveFace	Specifies which side of the Plate is active. The active side of the plate generates an SRP (solar radiation pressure) force when the Spacecraft's ForceModel is configured with ForceModel.SRP = 1 and ForceModel.SRPForceGeometry = 1. The inactive side of the plate is transparent to SRP, and therefore generates no SRP force. The nominally active face is determined by the order that the vertices are specified: the right-hand rule is applied to the first three vertices to determine the direction of the normal vector for the plate. You can reverse the normal vector direction and change the active face for the plate by setting ActiveFace to 1, or by changing the order that the vertices are specified.	Type: Variable Access: Read/Write
Area	The area of the plate, computed as the sum of the area of each triangle in the triangle strip that defines the plate's shape. For the area of a PlateModel projected along a particular direction, see PlateModel.GetIncidentArea() and PlateModel.SRPIncidentArea().	Type: Variable Access: Read-Only Units: m^2
ArticulationModel	The articulation model used by this plate. A value of 0 corresponds to a plate which does not track the Sun. A value of 1 corresponds to a plate which will rotate about its primary axis to track the Sun. A value of 2 corresponds to a plate which will rotate about its primary and secondary axes to track the Sun. To get the updated vertex locations and normal vector for this plate as it rotates to track the sun, use the Plate.GetUpdatedVertices() and Plate.GetUpdatedNormal() methods.	Type: Variable Access: Read/Write
CenterOfPressure	The center of pressure of the Plate in the Spacecraft's Body Coordinate System.	Type: Array Access: Read-Only Units: m
DeclaredName	The name of the object as declared.	Type: String Access: Read-Only
DiffuseReflectivity	The coefficient of diffuse reflectivity of this plate. Diffuse reflectivity is the reflection of light such that a ray incident on the surface is scattered. Reflectivity is the ratio of the power of the reflected wave to that of the incident wave. An increasing coefficient corresponds to a greater degree of scatter, thus decreasing power of the reflected wave. Note that the sum of DiffuseReflectivity and SpecularReflectivity must be less than or equal to 1.	Type: Variable Access: Read/Write
FaceColor	The color used to draw the face of this Plate in views.	Type: Variable Access: Read/Write
Name	The name displayed for this object in output windows such as views, plots, and reports.	Type: String Access: Read/Write
Normal	The normal vector of the plate in the Spacecraft Body Coordinate System frame. To get the updated normal vector for this plate as it rotates to track the sun, use the Plate.GetUpdatedNormal() method.	Type: Array Access: Read-Only
NormalColor	The color used to draw the normal vector of this Plate in views. Plate normals are drawn as lines originating from the center of each plate with a length determined by PlateModel.NormalsLength.	Type: Variable Access: Read/Write
NormalLength	The length of the Plate normal vector in meters when drawn in views.	Type: Variable Access: Read/Write Units: m
NumberOfVertices	The number of Vertices used to define this Plate.	Type: Variable Access: Read/Write
ObjectId	The unique identifier for the object.	Type: Variable Access: Read-Only
ObjectType	The type of the object.	Type: String Access: Read-Only
PrimaryPivotPoint	Used when the plate's articulation model is single-axis or two-axis sun tracking. The position of the pivot point of the plate's primary rotation axis in the Spacecraft's BCS frame.	Type: Array Access: Read/Write Units: m
PrimaryRotationAxis	Used when the plate's articulation model is single-axis or two-axis sun tracking. The vector describing the direction of the plate's primary rotation axis, specified in the Spacecraft Body Coordinate System.	Type: Array Access: Read/Write
PrimaryRotationAxisColor	The color used to draw the primary rotation axis of this Plate in views. This only has an effect when the Plate.ArticulationModel is single-axis sun tracking or two-axis sun tracking.	Type: Variable Access: Read/Write
PrimaryRotationAxisLength	The length of the primary rotation axis in meters when drawn in views. This only has an effect when the Plate.ArticulationModel is single-axis sun tracking or two-axis sun tracking.	Type: Variable Access: Read/Write Units: m
SecondaryRotationAxisColor	The color used to draw the secondary rotation axis of this Plate in views. This only has an effect when the Plate.ArticulationModel is two-axis sun tracking.	Type: Variable Access: Read/Write
SecondaryRotationAxisIntercept	Used only when the plate's articulation model is two-axis sun tracking. This property specifies the location where the second rotation axis intersects the primary rotation axis. This value is measured from the primary pivot point along the primary rotation axis. The value can be positive or negative.	Type: Variable Access: Read/Write Units: m
SecondaryRotationAxisLength	The length of the secondary rotation axis in meters when drawn in views. This only has an effect when the Plate.ArticulationModel is two-axis sun tracking.	Type: Variable Access: Read/Write Units: m
SpecularReflectivity	The coefficient of specular reflectivity of this plate. Specular reflectivity is the mirror-like reflection of light from a surface, where each incident ray is reflected at the same angle to the surface normal as the incident ray. Reflectivity is the ratio of the power of the reflected wave to that of the incident wave. An increasing coefficient responds to increasing power of the reflected wave. Note that the sum of DiffuseReflectivity and SpecularReflectivity must be less than or equal to 1.	Type: Variable Access: Read/Write
SRPAreaScaleFactor	Scales the force generated due to solar radiation pressure on this plate. Can be specified by the user to simulate "self-shadowing" where one plate generates less force because it's behind another plate.	Type: Variable Access: Read/Write
Vertices	A matrix containing the vertices used to define this plate. The plate is defined using a triangle strip, where every three vertices defines a triangle. The plate's normal direction is defined using the right hand rule. The vertices for a given plate must be coplanar. To get the updated vertex locations for this plate as it rotates to track the sun, use the Plate.GetUpdatedVertices() method.	Type: Matrix Access: Read/Write Units: m
WireframeColor	The color used to draw the borders of this Plate in views.	Type: Variable Access: Read/Write

Name	Description
ClearSavedStates	Clears previous saved states for this object.
ConfigureCircularShape	Configures this Plate with a circular shape. The Plate will be a circle with the specified radius. The center of the plate will be located at the specified centerPosition in the Spacecraft's body coordinate system. The plate's orientation is specified using the normal argument. The numberOfSegments argument controls how many triangles are used to approximate the circular shape. You must set the Spacecraft's ForceModel.SRPForceGeometry to "PlateModel" for this to have an effect.
ConfigureRectangularShape	Configures this Plate with a rectangular shape. The Plate will be a rectangle with dimensions dim1 and dim2, which are measured along direction1 and direction2 in the Spacecraft's body coordinate system. The center of the plate will be located at the specified centerPosition. You must set the Spacecraft's ForceModel.SRPForceGeometry to "PlateModel" for this to have an effect.
GetFromFile	Load the object state from the specified FreeFlyer object file.
GetFromString	Load the object state from the specified string.
GetSRPForce	Returns the current SRP force on the Plate in the specified reference frame. In order for the PlateModel to have an effect on the Spacecraft's propagation, the Spacecraft's ForceModel must be configured correctly. Turn on SRP using ForceModel.SRP = 1, and then choose PlateModel-based SRP using ForceModel.SRPForceGeometry = 1.
GetSRPTorque	Returns the current SRP torque on the Plate about the origin of the Spacecraft BCS. The torque is computed in the Spacecraft body fixed frame.
GetUpdatedCenterOfPressure	Returns the updated center of pressure for this plate as it points to track the sun according to the plate's ArticulationModel. The center of pressure is given in the Spacecraft's body coordinate system.
GetUpdatedNormal	Returns the updated normal vector for this plate as it points to track the sun according to the plate's ArticulationModel. The normal vector is given in the Spacecraft's body coordinate system.
GetUpdatedVertices	Returns the updated locations of the plate's vertices as it points to track the sun according to the plate's ArticulationModel. The vertex locations are given in the Spacecraft's body coordinate system.
PutToFile	Convert the object state to FreeFlyer object xml and write to a file.
PutToString	Convert the object state to FreeFlyer object xml and return as a string.
ReferenceEquals	Returns 1 if the argument refers to the calling object and 0 otherwise.
Restore	Restore an object's state from a previously saved state.
Save	Save the object's state so that it can be restored later.

Plate Object

Description

Available In Editions:

Timing Precision Mode