ORExInitializer

giant.ufo.state_initializer:

class giant.ufo.state_initializer.ORExInitializer(scene: giant.ray_tracer.scene.Scene, initial_range: numbers.Real | None = None, initial_cram: numbers.Real = 0.001, range_variance: numbers.Real = 49.0, measurement_covariance_multiplier: numbers.Real = 9.0, initial_velocity_variance: Sequence | numpy.ndarray | numbers.Real = 1e-06, initial_cram_variance: numbers.Real = 1.0, minimum_initial_radius: numbers.Real = 0.25)[source]
Parameters:

  • scene (Scene) –

  • initial_range (Real | None) –

  • initial_cram (Real) –

  • range_variance (Real) –

  • measurement_covariance_multiplier (Real) –

  • initial_velocity_variance (Sequence | ndarray | Real) –

  • initial_cram_variance (Real) –

  • minimum_initial_radius (Real) –

initial_range: Real | None = None

The initial range to the target as a number or None.

If this is None, then the initial range to the target will be the same as the range from the camera to the central body assumed to be the first target in the scene attribute.

initial_cram: Real = 0.001

The initial CrAm value for the filter in m**2/kg.

See the SolRadAndGravityDynamics class for details.

range_variance: Real = 49.0

The initial range variance in km**2 for computing the initial state covariance.

This is used along with the measurement covariance to compute the initial position covariance matrix.

measurement_covariance_multiplier: Real = 9.0

The multiplier to use on the measurement covariance when computing the state covariance.

Because this is applied to the covariance it is essentially a sigma**2 multiplier (so a value of 9 is saying use the 3 sigma measurement uncertainty).

initial_velocity_variance: Sequence | ndarray | Real = 1e-06

The initial velocity variance in units of (km/s)**2

This can be specified as a scalar, in which case it is assumed that all 3 axes are the specified value, a 1d array of length 3 in which case the covariance matrix is formed with this as the main diagonal, or a 2d array of shape 3x3 in which case the covariance matrix is directly used. Note that if you specify the full covariance matrix it must be symmetric.

initial_cram_variance: Real = 1.0

The initial CrAm variance in units of (m**2/kg)**2.

Summary of Methods