pydda.cost_functions.calculate_radial_vel_cost_function

pydda.cost_functions.calculate_radial_vel_cost_function(vrs, azs, els, u, v, w, wts, rmsVr, weights, coeff=1.0)[source]

Calculates the cost function due to difference of the wind field from radar radial velocities. For more information on this cost function, see Potvin et al. (2012) and Shapiro et al. (2009).

All arrays in the given lists must have the same dimensions and represent the same spatial coordinates.

Parameters
vrs: List of float arrays

List of radial velocities from each radar

els: List of float arrays

List of elevations from each radar

azs: List of float arrays

List of azimuths from each radar

u: Float array

Float array with u component of wind field

v: Float array

Float array with v component of wind field

w: Float array

Float array with w component of wind field

wts: List of float arrays

Float array containing fall speed from radar.

rmsVr: float

The sum of squares of velocity/num_points. Use for normalization of data weighting coefficient

weights: n_radars x_bins x y_bins float array

Data weights for each pair of radars

coeff: float

Constant for cost function

Returns
J_o: float

Observational cost function

References

Potvin, C.K., A. Shapiro, and M. Xue, 2012: Impact of a Vertical Vorticity Constraint in Variational Dual-Doppler Wind Analysis: Tests with Real and Simulated Supercell Data. J. Atmos. Oceanic Technol., 29, 32–49, https://doi.org/10.1175/JTECH-D-11-00019.1

Shapiro, A., C.K. Potvin, and J. Gao, 2009: Use of a Vertical Vorticity Equation in Variational Dual-Doppler Wind Analysis. J. Atmos. Oceanic Technol., 26, 2089–2106, https://doi.org/10.1175/2009JTECHA1256.1