Class in Zendir.Classes | Inherits from RADAR

Declaration

class SyntheticApertureRADAR;

Description

The Synthetic Aperture RADAR (SAR) class is able to detect the presence of objects within the simulation. This requires a RADAR sensor to be attached to the spacecraft or ground object and will produce maps and textures when the sensor is active and is using a visualization engine.


Properties

DeclaredDescription
CompressVisualisationWhen true, the texture visualisation compresses the depth colour gradient tospan only the actual hit range (nearest hit to farthest hit) rather than0 to max sensor range. This gives much better contrast when hits occupy anarrow band of the total range.
RangeMaximum range of the sensor in metres.Defaults to max value of 10,000km.
ResolutionThe resolution of the output samples
SampleRateThe time between RADAR samples
InheritedDescription
AlignmentErrorPitch-axis boresight misalignment applied by error models.This is a rotation about the local Right axis.
ApertureDiameterThe diameter of the antenna aperture, which sets how much gain the antenna hasand how narrow its beam is. A larger aperture concentrates the sametransmitted power into a narrower beam, so it returns a stronger signal from asmaller patch of sky.
ApertureEfficiencyThe fraction of the aperture area that contributes to the gain, which accountsfor the illumination taper, the blockage and the surface error of a realantenna. A value of one describes a uniformly illuminated aperture, where areflector is typically around 0.6.
BandwidthThe bandwidth of the RADAR signal, which is measured in Hz
BeamwidthThe half-power beamwidth of the antenna, which is the angle across themainlobe between the two directions where the gain has fallen to half of itspeak. A target further off the boresight than half of this returns less thanhalf the power that the same target would on it.
BehavioursA collection of behaviours attached to this object.
CanCaptureFlagWhether the radar is allowed to capture. Defaults to true so a radarwithout a power model still measures. When ais attached, it clears this flag during abrownout so that an under-voltage receiver cannot report a return.
CaptureOnTickA flag whether the sensor should capture the data each frame.
CenterOfMassB_BThe center of mass of the component in respect to the body frame (B) of the component. This is isolated from anychildren and exists in isolation.
CenterOfMassDot_LB_BThe center of mass time-derivative of the component within its own local coordinates. This does not include anyof the sub-components and exists in isolation.
CenterOfMassDotB_BThe center of mass time-derivative of the component relative to the body frame (B). This does not include any ofthe sub-components and exists in isolation.
CenterOfMassL_LThe center of mass of the component within its own local coordinates. This does not include any of thesub-components and exists in isolation.
CenterOfMassPrime_LB_BThe center of mass general-derivative of the component within its own local coordinates. This does not includeany of the sub-components and exists in isolation.
CenterOfMassPrimeB_B[m/s] The center of mass general-derivative of the component relative to the body frame (B). This does notinclude any of the sub-components and exists in isolation.
ChildrenA collection of children attached to this object.
CoverageBodyNameThe celestial body name this sensor is registered with in the PlanetCoverageSystem, or null if not registered.
DCM_BNThe rotational DCM matrix between the body frame (B) at the top of this component chain and the inertial frame (N).
DCM_LBThe rotational DCM matrix between the component frame of this object (L) relative to the body frame (B).
DCM_LNThe DCM rotational matrix of the component relative to the inertial origin (N) of the world.
DCM_LPThe DCM matrix of the component in the parent’s frame (P), taken from the Component Transform (PL).
DetectionThresholdThe detection threshold of the RADAR system, which is used to determinethe minimum signal strength required to detect an object.
DistanceNoiseThe noise for calculating the distance to the target, as a fraction of the distance.
FaultStateSpecification used if state is set to a fault state for the sensor.This will be able to define how the output data is set for this particularsensor.
FieldOfViewThe full angle of the mainlobe of the antenna, which is twice the half-powerbeamwidth and so reaches out to where the pattern has fallen away. Nothingoutside this cone is sensed at all. Setting this resizes the aperture to theone that produces the requested mainlobe, which moves the gain to match.
GainThe peak gain of the antenna along its boresight, which follows from theaperture measured in wavelengths rather than being set on its own. Gain andbeamwidth are two descriptions of the same aperture, so setting them apartfrom one another would let the sensor claim a gain that its beam cannotsupport.
IgnoreSignalOutsideThresholdA flag whether a return outside the range the receiver can measure is discardedrather than held at the limit it passed. A discarded target is not sensed atall, so it cannot be detected and nothing is reported about it, where holding itat the limit still reports a target at a signal it never returned.
In_DeviceStatusMsgThe Device status message for the physical component whetherthe device is available.
In_TransformMsgThe transform message associated with the root object ofthis particular sensor. This is required for the base levelposition and rotation of the object.
IsDetectedA boolean value indicating if a target has been detected by the RADAR sensor,based on the signal to noise ratio and the sensor’s detection threshold.
IsEnabledIs true if the object is currently enabled.
LocalForwardThe direction of the transform frame’s forward vector, which is along the Y axis.
LocalRightThe direction of the transform frame’s right vector, which is along the X axis.
LocalUpThe direction of the transform frame’s up vector, which is along the Z axis.
MassThe component mass defined in the object. This is independent of any parent or children objects and exists inisolation.
MassDotThe component mass time-derivative defined in the object. This is independent of any parent or children objectsand exists in isolation.
MaxSignalThe strongest return the receiver is able to report, which is the level itsfront end saturates at. A return above this reads at the ceiling rather than atthe level it arrived with. The default is a milliwatt, which is where a receiverwith the sensitivity to sit on a thermal noise floor is normally driven intocompression.
MinSignalThe weakest return the receiver is able to report, which is the floor its ownfront end produces. A return below this reads at the floor rather than at thelevel it arrived with, as a receiver cannot report a signal it cannot lift outof itself.
ModelsA collection of models attached to this object.
MomentOfInertia_LBThe moment of inertia of the component, measured at the local center of mass, represented with its own localcoordinates. This does not include any of the sub-components and exists in isolation.
MomentOfInertiaB_BThe moment of inertia of this component, measured in the body frame relative to the parented body. This isindependent of any children and exists in isolation.
MomentOfInertiaPrime_LBThe derivative of the moment of inertia of the component, measured at the local center of mass, represented withits own local coordinates. This does not include any of the sub-components and exists in isolation.
MomentOfInertiaPrimeB_BThe derivative of the moment of inertia of the component, represented in the body frame (B). This is independentand exists in isolation.
NameThe display name or tag of this object.
NumTargetsThe number of targets that the RADAR sensor can see.
OperationStateCurrent operational state of the sensor.
Out_ComponentMassMsgThe component mass message defines the set of mass properties and states of the system within this componentlocally. This is independent of any parent or children properties or objects.
Out_PlanetCoverageMsgOutput message holding this sensor’s cumulative planet coverage (heat map over the celestial body).Values are accumulated dwell time [s] per cell; TotalCoverage is the fraction of cells ever covered(count of non-zero Values / total cells) and does not decrease.Only updated if the sensor is registered with the PlanetCoverageSystem; the message is reset when registered.
Out_RADARDataMsgThe RADAR data message that is output by the RADAR sensor.
Out_TransformMsgThis defines the base transform message that stores the state of the transform of this object.
ParentThe currently attached parent object (if any).
Position[m] The position of the object relative to the parent or to world origin, if no parent exists.
Position_BN_NThe position of the body (the root parent B) in the inertial frame relative to the inertial point (N).
Position_LB_BThe position of the component relative to the root object of this hierarchy. This is in the inertial frame and ifthe component is the root object, then there will be no position.
Position_LN_NThe position of the inertial world space. This position is derived from the world’s transform (N).
Position_LP_PThe position of the object relative to the parented object (P). If there is no parent object, then this will bein the inertial frame.
PowerThe transmitter power when sending a signal
RootThe root object in the parent chain.
Rotation[-] The rotation of the object relative to the parent or to the world origin, if no parent exists.
SignalDistanceThe estimated distance to the target detected by the RADAR sensor.
SignalToNoiseThe signal to noise of the RADAR sensor, calculated as the total signaldivided by the total noise.
TargetAzimuthThe bearing of the target measured in the plane spanned by the boresight andthe right axis of the sensor. Together with the elevation this locates thetarget relative to the boresight, and both are zero when the target lies alongit.
TargetCrossSectionThe radar cross-section that the target presented to the sensor, after anyreduction applied when the target over-fills the beam and so is only partlyilluminated by it.
TargetDopplerShiftThe Doppler shift of the signal returned by the target, which is positive whenthe target is closing on the sensor.
TargetElevationThe bearing of the target measured out of the plane spanned by the boresightand the right axis of the sensor.
TargetRangeThe range from the sensor to the surface of the target it is reporting on. Thisis the true range, where SignalDistance is the same range with the measurementnoise of the sensor applied.
TargetRangeRateThe rate the range to the target is changing at, which is positive when thetarget is moving away from the sensor. This stays zero until the target hasbeen sensed on two separate captures.
TargetSelectionThe rule used to choose which of the detected targets the sensor reports on.Every target that clears the detection threshold is a candidate, and thisdecides between them. When no target clears the threshold the strongestreturn is reported regardless, so that the sensor still describes what itcan see.
TemperatureThe temperature of the RADAR system, which is used to calculatethe noise floor of the system.
Thermal[TEMPORARY] A reference to the thermal model that is attached to this object. This will allow the object to havethermal properties and be able to be used in thermal simulations.
TotalNoiseThe total noise of the RADAR sensor.
TotalSignalThe total signal of the RADAR sensor, which is the sum of all target signals.
WavelengthThe wavelength of the RADAR signal, typically an X-band wavelength willbe sub-meter, while a L-band wavelength will be in the meter range. Awavelength of zero carries no signal, so the range starts above it. Thismeasures the aperture, so it sets the gain and the beamwidth alongside it.

Methods

DeclaredDescription
OnPingExecuted when a sample is created through Unrealand will ping the components.
InheritedDescription
AddObjectReturns a new simulation object with the specified type.
AddTargetAdds a target to the list of targets that the RADAR sensor can sense. Thiswill create a new target with the specified parameters.
AttachAttempts to attach this object to a new parent. This will only work if the current object is no parented to anyother object.
CaptureA method that will capture the data of the payload and store it insome form of byte array.
ClearBufferClears the cache of the RADAR sensor, which will remove all datafrom the output message.
ContainsModelWithIDReturns true if an attached model satisfies the specified ID.
ContainsModelWithTypeReturns true if an attached model satisfies the specified type.
DefineAreaOfInterestDefines a new area of interest with finer grid resolution for coverage tracking.
DetachThis is an action to detach the current object from its parent, if it exists and move it to another object or tojust exist within the simulation.
FindBehavioursWithTypeReturns all attached behaviours that satisfies the specified type.
FindBehaviourWithIDReturns an attached behaviour that satisfies the specified ID.
FindBehaviourWithTypeReturns an attached behaviour that satisfies the specified type.
FindChildrenWithTypeReturns all attached children that satisfies the specified type.
FindChildWithIDReturns an attached child that satisfies the specified ID.
FindChildWithTypeReturns an attached child that satisfies the specified type.
FindModelsWithTypeReturns all attached models that satisfies the specified type.
FindModelWithIDReturns an attached model that satisfies the specified ID.
FindModelWithTypeReturns an attached model that satisfies the specified type.
FindParentWithIDReturns an attached parent that satisfies the specified ID.
FindParentWithTypeReturns an attached parent that satisfies the specified type.
FindRootWithIDReturns a root object that satisfies the specified ID.
FindRootWithTypeReturns a root object that satisfies the specified type.
GetAreaOfInterestIdsReturns the Ids of all defined areas of interest, optionally filtered by body name.
GetBodyCoverageForLatLongReturns the accumulated dwell time [s] or sensor-seconds at a specific latitude and longitude for all sensorsregistered for the given celestial body. Auto-routes to the finest AOI containing the point.
GetBoresightDirection_NReturns the effective boresight direction in the inertial frame,accounting for any alignment error applied by error models.
GetCoverageForLatLongReturns the accumulated dwell time [s] at a specific latitude and longitude for this sensor.
GetDynamicSensorRotationReturns the sensor rotation with any alignment error applied.The alignment error is a pitch rotation about the local Right axis.
GetModelReturns a valid assigned model with the specified type.
GetResolutionForLatLongReturns the best (minimum) resolution achieved at a specific latitude and longitude for this sensor.For Camera sensors this is GSD [m]; for other RemoteSensors this is FOV ground width [m].
GetSensorAoiCoverageMessageReturns this sensor’s accumulated coverage message for an AOI.
GetTotalAoiCoverageMessageReturns the accumulated AOI coverage message from all sensors registered for the AOI’s body.
GetTotalPlanetCoverageReturns the total planet coverage from all sensors registered for the specified celestial body.
GetWorldForward[DEPRECATED] THIS FUNCTION WILL BE REMOVED AND SHOULD NOT BE USED.
GetWorldRight[DEPRECATED] THIS FUNCTION WILL BE REMOVED AND SHOULD NOT BE USED.
GetWorldTransformReturns the world transform of the object which is relative to the parent. If no parent exists, this will be thetransform of the object in world space.
GetWorldUp[DEPRECATED] THIS FUNCTION WILL BE REMOVED AND SHOULD NOT BE USED.
IsGroundObjectDetectableReturns whether a ground object is detectable by this sensor based on coverage and resolution.An object is detectable if it was observed and the sensor’s resolution at that location isequal to or better (smaller) than the specified object size.
ReadBodyTransformThis method will reset the dirty flag on the mass so that it has been read successfully and is valid.
RegisterWithCoverageSystemRegisters this sensor with the PlanetCoverageSystem for celestial body coverage analysis.
RemoveAreaOfInterestRemoves an area of interest and clears its accumulated coverage data.
RemoveTargetRemoves a target from the list of targets that the RADAR sensor can see.
SetRandomSeedSets the random seed used for the distance noise of the sensor, so that ascenario reports the same measurements every time it is run.
SetWorldTransform[DEPRECATED] THIS FUNCTION WILL BE REMOVED AND SHOULD NOT BE USED.
UnregisterFromCoverageSystemDeregisters this sensor from the PlanetCoverageSystem.
UpdateMassPropertiesUpdates the mass properties of the current physical object at a particular time.
WasGroundObjectObservedReturns whether a ground object’s location was ever observed by this sensor.
WasLocationObservedReturns whether this sensor has observed the given latitude and longitude at least once.