navlie.lib.models.Gravitometer¶
- class navlie.lib.models.Gravitometer(R: ndarray, gravity_vector: List[float] | None = None)¶
Bases:
MeasurementModelGravitometer model of the form
\[\mathbf{y} = \mathbf{C}_{ab}^T \mathbf{g}_a + \mathbf{v}\]where \(\mathbf{g}_a\) is the magnetic field vector in a world frame a.
Compatible with
SO3State, SE3State, SE23State, IMUState.- Parameters:
R (np.ndarray) – Covariance associated with \(\mathbf{v}\)
gravity_vector (list[float] or numpy.ndarray, optional) – local magnetic field vector, by default [0, 0, -9.80665]
- evaluate(x: MatrixLieGroupState)¶
Evaluates the measurement model \(\mathbf{g}(\mathcal{X})\).
- jacobian(x: MatrixLieGroupState)¶
Evaluates the measurement model Jacobian with respect to the state.
\[\mathbf{G} = \frac{D \mathbf{g}(\mathcal{X})}{D \mathcal{X}}\]
- covariance(x: MatrixLieGroupState) → ndarray¶
Returns the covariance \(\mathbf{R}\) associated with additive Gaussian noise.
- evaluate_with_jacobian(x: State) → Tuple[ndarray, ndarray]¶
Evaluates the measurement model and simultaneously returns the Jacobian as its second output argument. This is useful to override for performance reasons when the model evaluation and Jacobian have a lot of common calculations, and it is more efficient to calculate them in the same function call.