pydda.cost_functions.calculate_grad_radial_vel

pydda.cost_functions.calculate_grad_radial_vel(vrs, els, azs, u, v, w, wts, weights, rmsVr, coeff=1.0, upper_bc=True)

Calculates the gradient of the cost function due to difference of wind field from radar radial velocities. 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 azimuths) – 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

• coeff (float) – Constant for cost function

• vel_name (str) – Background velocity field name

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

Returns:

• y (1-D float array) – Gradient vector of observational cost function.

• More information

• —————-

• The gradient is calculated by taking the functional derivative of the

• cost function. For more information on functional derivatives, see the

• Euler-Lagrange Equation

• https (//en.wikipedia.org/wiki/Euler%E2%80%93Lagrange_equation)