Module: radiationPressure
Executive Summary
Radiation pressure dynamics class used to compute
The module
PDF Description
contains further information on this module’s function,
how to run it, as well as testing.
Message Connection Descriptions
The following table lists all the module input and output messages. The module msg variable name is set by the user from python. The msg type contains a link to the message structure definition, while the description provides information on what this message is used for.
Msg Variable Name |
Msg Type |
Description |
|---|---|---|
sunEphmInMsg |
sun state input message |
|
sunEclipseInMsg |
(optional) sun eclipse input message |
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class RadiationPressure : public SysModel, public DynamicEffector
- #include <radiationPressure.h>
solar radiation pressure dynamic effector
Public Functions
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RadiationPressure()
This is the constructor. It sets some default initializers that can be overriden by the user.
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~RadiationPressure()
The destructor. Nothing of note is performed here
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void Reset(uint64_t CurrentSimNanos)
Reset the module to origina configuration values.
- Returns:
void
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void UpdateState(uint64_t CurrentSimNanos)
Update model state by reading in new message data
- Parameters:
CurrentSimNanos – current simulation time in nanoseconds
- Returns:
void
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void linkInStates(DynParamManager &statesIn)
This method retrieves pointers to parameters/data stored in the dynamic parameter manager
- Parameters:
states – Dynamic parameter manager
- Returns:
void
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void readInputMessages()
This method is used to read the incoming ephmeris and spacecraft state messages. The data is stored in the associated buffer structure.
- Returns:
void
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void computeForceTorque(double integTime, double timeStep)
This method computes the dynamic effect due to solar raidation pressure. It is an inherited method from the DynamicEffector class and is designed to be called by the simulation dynamics engine.
- Parameters:
integTime – Current simulation integration time
timeStep – Current integration time step used
- Returns:
void
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void setUseCannonballModel()
Sets the model to the cannonball model in computing the solar radiation force
- Returns:
void
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void setUseFacetedCPUModel()
Sets the model to the faceted table-lookup model, evaluted on the CPU, in computing the solar radiation force
- Returns:
void
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void addForceLookupBEntry(Eigen::Vector3d vec)
Add force vector in the body frame to lookup table.
- Parameters:
vec – (N) Force vector for particular attitude in lookup table
- Returns:
void
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void addTorqueLookupBEntry(Eigen::Vector3d vec)
Add torque vector to lookup table.
- Parameters:
vec – (Nm) Torque vector for particular attitude in lookup table
- Returns:
void
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void addSHatLookupBEntry(Eigen::Vector3d vec)
Add sun unit direction vector in body frame to lookup table.
- Parameters:
vec – sun unit direction vector in body frame
- Returns:
void
Public Members
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double area
m^2 Body surface area
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double coefficientReflection
— Factor grouping surface optical properties
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ReadFunctor<SpicePlanetStateMsgPayload> sunEphmInMsg
— sun state input message
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ReadFunctor<EclipseMsgPayload> sunEclipseInMsg
— (optional) sun eclipse input message
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std::vector<Eigen::Vector3d> lookupForce_B
— Force on S/C at 1 AU from sun
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std::vector<Eigen::Vector3d> lookupTorque_B
— Torque on S/C
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std::vector<Eigen::Vector3d> lookupSHat_B
— S/C to sun unit vector defined in the body frame.
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BSKLogger bskLogger
— BSK Logging
Private Functions
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void computeCannonballModel(Eigen::Vector3d rSunB_B)
Computes the solar radiation force vector based on cross-sectional Area and mass of the spacecraft and the position vector of the spacecraft to the sun. The solar radiation pressure decreases quadratically with distance from sun (in AU)
Solar Radiation Equations obtained from Earth Space and Planets Journal Vol. 51, 1999 pp. 979-986
- Parameters:
s_N – (m) Position vector to the Sun relative to the inertial frame
- Returns:
void
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void computeLookupModel(Eigen::Vector3d rSunB_B)
Computes the solar radiation force vector using a lookup table given the current spacecraft attitude and the position vector of the spacecraft to the sun. It is assumed that the lookup table has been generated with a solar flux at 1AU. Force and torque values are scaled.
- Parameters:
s_B – (m) Position vector of the Sun relative to the body frame
- Returns:
void
Private Members
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srpModel_t srpModel
— specifies which SRP model to use
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SpicePlanetStateMsgPayload sunEphmInBuffer
— Buffer for incoming ephemeris message data
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bool stateRead
— Indicates a succesful read of incoming SC state message data
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EclipseMsgPayload sunVisibilityFactor
[-] scaling parameter from 0 (fully obscured) to 1 (fully visible)
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RadiationPressure()