Multi Target¶

Model of a spatial radar channel featuring multiple reflecting targets.

The following minimal example outlines how to configure the channel model within the context of a Simulation:

# Initialize a single device operating at 78.5 GHz
simulation = Simulation()
device = simulation.new_device(carrier_frequency=78.5e9)

# Create a radar channel modeling two targets at 10m and 50m distance
channel = MultiTargetRadarChannel(attenuate=False)
simulation.set_channel(device, device, channel)

first_target = VirtualRadarTarget(
    FixedCrossSection(1),
    StaticTrajectory(Transformation.From_Translation(np.array([10, 0, 0]))),
    static=False,
)
second_target = VirtualRadarTarget(
    FixedCrossSection(1),
    StaticTrajectory(Transformation.From_Translation(np.array([0, 50, 0]))),
    static=True,
)
channel.add_target(first_target)
channel.add_target(second_target)

# Configure an FMCW radar with 5 GHz bandwidth illuminating the target
radar = Radar(FMCW(10, 5e9, 90 / 5e9, 100 / 5e9))
device.add_dsp(radar)

# Configure a simulation evluating the radar's operating characteristics
simulation.add_evaluator(ReceiverOperatingCharacteristic(radar, device, device, channel))
simulation.new_dimension('noise_level', dB(np.arange(0, -22, -2).tolist()), device)
simulation.num_samples = 1000

# Run simulation and plot resulting ROC curve
result = simulation.run()
result.plot()

class MultiTargetRadarChannel(attenuate=True, interference=True, decorrelation_distance=inf, *args, **kwargs)[source]¶

Bases: RadarChannelBase[MultiTargetRadarChannelRealization], Serializable

Model of a spatial radar channel featuring multiple reflecting targets.

Parameters:

attenuate (bool, optional) – Should the propagated signal be attenuated during propagation modeling? Enabled by default.
interference (bool, optional) – Should the channel model consider interference between the linked devices? Enabled by default.
decorrelation_distance (float, optional) – Distance at which the channel’s random variable realizations are considered uncorrelated. \(\infty\) by default, meaning the channel is static in space.

_realize()[source]¶

Generate a new channel realzation.

Abstract subroutine of realize. Each Channel is required to implement their own _realize() method.

Returns: A new channel realization.

Return type:: MultiTargetRadarChannelRealization

add_target(target)[source]¶

Add a new target to the radar channel.

Parameters:: target (RadarTarget) – Target to be added.
Return type:: None

make_target(moveable, cross_section, *args, **kwargs)[source]¶

Declare a moveable to be a target within the radar channel.

Parameters:

moveable (Moveable) – Moveable to be declared as a target.
cross_section (RadarCrossSectionModel) – Radar cross section model of the target.
*args – Additional positional arguments passed to the target’s constructor.
**kwargs – Additional keyword arguments passed to the target’s constructor.

Returns:

The newly created target.

Return type:

PhysicalRadarTarget

recall_realization(group)[source]¶

Recall a realization of this channel type from its HDF serialization.

Parameters:: group (h5py.Group) – HDF group to which the channel realization was serialized.
Return type:: MultiTargetRadarChannelRealization

Returns: The recalled realization instance.

property decorrelation_distance: float¶

Decorrelation distance of the radar channel.

Raises:: ValueError – For decorrelation distances smaller than zero.

interfernce: bool¶

Consider interference between linked devices.

Only applies in the bistatic case, where transmitter and receiver are two dedicated device instances.

property targets: Set[RadarTarget]¶: Set of targets considered within the radar channel.

class MultiTargetRadarChannelRealization(consistent_realization, phase_variable, targets, interference, attenuate, sample_hooks, gain)[source]¶

Bases: RadarChannelRealization

Realization of a spatial multi target radar channel.

Generated by the realize method of MultiTargetRadarChannel.

_summary_

Parameters:

sample_hooks (Set[ChannelSampleHook[CST]], optional) – Hooks to be called after the channel is sampled.
gain (float) – Linear power gain factor a signal experiences when being propagated over this realization.

static From_HDF(group, phase_variable, targets, sample_hooks)[source]¶

Return type:: MultiTargetRadarChannelRealization

to_HDF(group)[source]¶

Serialize the channel realization to HDF5.

Parameters:: group (Group) – HDF5 group to serialize the channel realization to.
Return type:: None

class RadarTarget(static=False)[source]¶

Bases: ABC

Abstract base class of radar targets.

Radar targets represent reflectors of electromagnetic waves within RadarChannelBase instances.

Parameters:: static (bool, optional) – Is the target visible during null hypothesis testing? Disabled by default.

abstract sample_cross_section(impinging_direction, emerging_direction)[source]¶

Query the target’s radar cross section.

The target radr cross section is denoted by the vector \(\sigma_{\ell}\) within the respective equations.

Parameters:

impinging_direction (Direction) – Direction from which a far-field source impinges onto the target model.
emerging_direction (Direction) – Direction in which the scatter wave leaves the target model.

Return type:

float

Returns: The assumed radar cross section in \(m^2\).

abstract sample_trajectory(timestamp)[source]¶

Sample the target’s trajectory at a given time.

Parameters:: timestamp (float) – Time at which to sample the trajectory in seconds.
Return type:: TrajectorySample

Returns: A sample of the trajectory.

property static: bool¶: Is the target visible in the null hypothesis?

class VirtualRadarTarget(cross_section, trajectory=None, static=False)[source]¶

Bases: Moveable, RadarTarget, Serializable

Model of a spatial radar target only existing within a channe link.

Parameters:

cross_section (RadarCrossSectionModel) – The assumed cross section model.
trajectory (Trajectory, optional) – The assumed trajectory of the target. By default, the target is assumed to be static.
static (bool, optional) – See RadarTarget.static(). Disabled by default.

sample_cross_section(impinging_direction, emerging_direction)[source]¶

Query the target’s radar cross section.

The target radr cross section is denoted by the vector \(\sigma_{\ell}\) within the respective equations.

Parameters:

impinging_direction (Direction) – Direction from which a far-field source impinges onto the target model.
emerging_direction (Direction) – Direction in which the scatter wave leaves the target model.

Return type:

float

Returns: The assumed radar cross section in \(m^2\).

sample_trajectory(timestamp)[source]¶

Sample the target’s trajectory at a given time.

Parameters:: timestamp (float) – Time at which to sample the trajectory in seconds.
Return type:: TrajectorySample

Returns: A sample of the trajectory.

property cross_section: RadarCrossSectionModel¶: The represented radar cross section model.

class PhysicalRadarTarget(cross_section, moveable, static=False)[source]¶

Bases: RadarTarget, Serializable

Model of a spatial radar target representing a moveable object.

The radar target will always be modeled at its moveable global position.

Parameters:

cross_section (RadarCrossSectionModel) – The assumed cross section model.
moveable (Moveable) – The moveable object this radar target represents.
static (bool, optional) – See RadarTarget.static(). Disabled by default.

sample_cross_section(impinging_direction, emerging_direction)[source]¶

Query the target’s radar cross section.

The target radr cross section is denoted by the vector \(\sigma_{\ell}\) within the respective equations.

Parameters:

impinging_direction (Direction) – Direction from which a far-field source impinges onto the target model.
emerging_direction (Direction) – Direction in which the scatter wave leaves the target model.

Return type:

float

Returns: The assumed radar cross section in \(m^2\).

sample_trajectory(timestamp)[source]¶

Sample the target’s trajectory at a given time.

Parameters:: timestamp (float) – Time at which to sample the trajectory in seconds.
Return type:: TrajectorySample

Returns: A sample of the trajectory.

property cross_section: RadarCrossSectionModel¶: The represented radar cross section model.

property moveable: Moveable¶

Moveble this radar model is attached to.

Returns: Handle to the moveable object.

class RadarCrossSectionModel[source]¶

Bases: ABC

Base class for spatial radar cross section models.

abstract get_cross_section(impinging_direction, emerging_direction)[source]¶

Query the model’s cross section.

Parameters:

impinging_direction (Direction) – Direction from which a far-field source impinges onto the cross section model.
emerging_direction (Direction) – Direction in which the scatter wave leaves the cross section model.

Return type:

float

Returns: The assumed cross section in \(m^2\).

class FixedCrossSection(cross_section)[source]¶

Bases: RadarCrossSectionModel

Model of a fixed cross section.

Can be interpreted as a spherical target floating in space.

Parameters:: cross_section (float) – The cross section in \(\mathrm{m}^2\).

get_cross_section(_, __)[source]¶

Query the model’s cross section.

Parameters:

impinging_direction (Direction) – Direction from which a far-field source impinges onto the cross section model.
emerging_direction (Direction) – Direction in which the scatter wave leaves the cross section model.

Return type:

float

Returns: The assumed cross section in \(m^2\).

property cross_section: float¶

The assumed cross section.

Returns: The cross section in \(\mathrm{m}^2\).

Raises:: ValueError – For cross sections smaller than zero.