pydda.retrieval.DDParameters#

class pydda.retrieval.DDParameters[source]#

This is a helper class for inserting more arguments into the pydda.cost_functions.J_function() and pydda.cost_functions.grad_J() function. Since these cost functions take numerous parameters, this class will store the needed parameters as one positional argument for easier readability of the code.

In addition, class members can be added here so that those contributing more constraints to the variational framework can add any parameters they may need.

Variables:

  • vrs (List of float arrays) – List of radial velocities from each radar

  • azs (List of float arrays) – List of azimuths from each radar

  • els (List of float arrays) – List of elevations from each radar

  • wts (List of float arrays) – Float array containing fall speed from radar.

  • u_back (1D float array (number of vertical levels)) – Background u wind

  • v_back (1D float array (number of vertical levels)) – Background v wind

  • u_model (list of 3D float arrays) – U from each model integrated into the retrieval

  • v_model (list of 3D float arrays) – V from each model integrated into the retrieval

  • w_model – W from each model integrated into the retrieval

  • Co (float) – Weighting coefficient for data constraint.

  • Cm (float) – Weighting coefficient for mass continuity constraint.

  • Cx (float) – Smoothing coefficient for x-direction

  • Cy (float) – Smoothing coefficient for y-direction

  • Cz (float) – Smoothing coefficient for z-direction

  • Cb (float) – Coefficient for sounding constraint

  • Cv (float) – Weight for cost function related to vertical vorticity equation.

  • Cmod (float) – Coefficient for model constraint

  • Cpoint (float) – Coefficient for point constraint

  • Ut (float) – Prescribed storm motion. This is only needed if Cv is not zero.

  • Vt (float) – Prescribed storm motion. This is only needed if Cv is not zero.

  • grid_shape – Shape of wind grid

  • dx – Spacing of grid in x direction

  • dy – Spacing of grid in y direction

  • dz – Spacing of grid in z direction

  • x – E-W grid levels in m

  • y – N-S grid levels in m

  • z – Grid vertical levels in m

  • rmsVr (float) – The sum of squares of velocity/num_points. Use for normalization of data weighting coefficient

  • weights (n_radars by z_bins by y_bins x x_bins float array) – Data weights for each pair of radars

  • bg_weights (z_bins by y_bins x x_bins float array) – Data weights for sounding constraint

  • model_weights (n_models by z_bins by y_bins by x_bins float array) – Data weights for each model.

  • point_list (list or None) – point_list: list of dicts List of point constraints. Each member is a dict with keys of “u”, “v”, to correspond to each component of the wind field and “x”, “y”, “z” to correspond to the location of the point observation in the Grid’s Cartesian coordinates.

  • roi (float) – The radius of influence of each point observation in m.

  • upper_bc (int) –

    The upper boundary (impermeability) condition:

    • 0 to not enforce impermeability at the top of the domain,

    • 1 to enforce w=0 at the top of the domain,

    • 2 to enforce w=0 above the echo top (or above, whichever is higher).

    The legacy booleans True and False are equivalent to 1 and 0.

  • above (float) – The minimum height of the echo top impermeability condition in km. The condition given by upper_bc = 2 is never applied below this level.

  • upper_bc_mask (3D bool array or None) – The grid points at which w is held fixed when upper_bc is 2, as returned by pydda.cost_functions.calculate_echo_top_mask(). This is calculated by PyDDA at the start of the retrieval.