Sidereon.SourceLocalization (Sidereon v0.22.0)

Source localization from time of arrival or time difference of arrival.

Sensors are fixed 2D or 3D Cartesian positions in metres. Arrival times and origin times are seconds. The propagation speed is metres per second, with an optional per-sensor override for simple per-path timing differences.

Summary

Types

source_error()

Functions

chan_ho_initial_guess(sensors, arrival_times_s, propagation_speed_m_s, mode \\ :toa)

Compute the closed-form Chan-Ho seed used by locate_source/4.

locate_source(sensors, arrival_times_s, propagation_speed_m_s, opts \\ [])

Locate a source from sensor arrival times.

sensor(position_m, propagation_speed_m_s \\ nil)

Convenience constructor for Sidereon.SourceLocalization.Sensor.

source_crlb(sensors, source_position_m, propagation_speed_m_s, timing_sigma_s)

Compute a timing Cramer-Rao lower bound for a proposed source location.

source_dop(sensors, source_position_m, propagation_speed_m_s)

Compute timing DOP for a proposed source location.

Types

source_error()

@type source_error() ::
  {:invalid_input, String.t(), String.t()}
  | {:too_few_sensors, non_neg_integer(), pos_integer()}
  | :initializer_singular
  | {:geometry, term()}
  | {:solver, String.t()}
  | {:did_not_converge, integer()}

Functions

chan_ho_initial_guess(sensors, arrival_times_s, propagation_speed_m_s, mode \\ :toa)

@spec chan_ho_initial_guess(
  [Sidereon.SourceLocalization.Sensor.t()],
  [number()],
  number(),
  Sidereon.SourceLocalization.Options.solve_mode()
) ::
  {:ok, Sidereon.SourceLocalization.InitialGuess.t()}
  | {:error, source_error() | :invalid_sensor | :invalid_mode}

Compute the closed-form Chan-Ho seed used by locate_source/4.

mode is :toa or {:tdoa, reference_sensor_index}.

locate_source(sensors, arrival_times_s, propagation_speed_m_s, opts \\ [])

@spec locate_source(
  [Sidereon.SourceLocalization.Sensor.t()],
  [number()],
  number(),
  keyword() | Sidereon.SourceLocalization.Options.t()
) ::
  {:ok, Sidereon.SourceLocalization.Solution.t()}
  | {:error,
     source_error() | :invalid_sensor | :invalid_position | :invalid_options}

Locate a source from sensor arrival times.

sensors is a list of Sensor structs. arrival_times_s must have matching length. propagation_speed_m_s is the default propagation speed in metres per second. Options are a keyword list or Sidereon.SourceLocalization.Options.

sensor(position_m, propagation_speed_m_s \\ nil)

@spec sensor([number()] | tuple(), number() | nil) ::
  Sidereon.SourceLocalization.Sensor.t()

Convenience constructor for Sidereon.SourceLocalization.Sensor.

source_crlb(sensors, source_position_m, propagation_speed_m_s, timing_sigma_s)

@spec source_crlb(
  [Sidereon.SourceLocalization.Sensor.t()],
  [number()] | tuple(),
  number(),
  number()
) ::
  {:ok, Sidereon.SourceLocalization.Crlb.t()}
  | {:error, source_error() | :invalid_sensor | :invalid_position}

Compute a timing Cramer-Rao lower bound for a proposed source location.

timing_sigma_s is the timing standard deviation in seconds used to scale the covariance.

source_dop(sensors, source_position_m, propagation_speed_m_s)

@spec source_dop(
  [Sidereon.SourceLocalization.Sensor.t()],
  [number()] | tuple(),
  number()
) ::
  {:ok, Sidereon.SourceLocalization.Crlb.dop()}
  | {:error, source_error() | :invalid_sensor | :invalid_position}

Compute timing DOP for a proposed source location.

The returned DOP values use the local Cartesian axes for horizontal and vertical split. Position DOP values multiply timing sigma in seconds to produce metres.