#!/usr/bin/env python
# -*- coding: utf-8 -*-
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"""Script to calculate optical flow advection velocities with option to
extrapolate."""
from improver import cli
[docs]@cli.clizefy
@cli.with_output
def process(
orographic_enhancement: cli.inputcube, *cubes: cli.inputcube,
):
"""Calculate optical flow components from input fields.
Args:
orographic_enhancement (iris.cube.Cube):
Cube containing the orographic enhancement fields.
cubes (iris.cube.CubeList):
Cubes from which to calculate optical flow velocities.
These three cubes will be sorted by their time coords.
Returns:
iris.cube.CubeList:
List of the umean and vmean cubes.
"""
from iris.cube import CubeList
from improver.nowcasting.optical_flow import generate_optical_flow_components
from improver.nowcasting.utilities import ApplyOrographicEnhancement
original_cube_list = CubeList(cubes)
# order input files by validity time
original_cube_list.sort(key=lambda x: x.coord("time").points[0])
# subtract orographic enhancement
cube_list = ApplyOrographicEnhancement("subtract")(
original_cube_list, orographic_enhancement
)
# calculate optical flow velocities from T-1 to T and T-2 to T-1, and
# average to produce the velocities for use in advection
u_mean, v_mean = generate_optical_flow_components(
cube_list, ofc_box_size=30, smart_smoothing_iterations=100
)
return CubeList([u_mean, v_mean])