Radarx

import radarx as rx
import xradar as xd
import cmweather  # noqa
import cartopy.crs as ccrs
from datetime import datetime

def filter_radar(ds):
    ds = ds.where((ds.reflectivity >= 0) & (ds.reflectivity <= 70))
    return ds

Grid Setup

x_lims = (-300e3, 250e3)
y_lims = (-250e3, 300e3)
z_lims = (0, 15e3)
h_res = 2000
v_res = 500

Load data

filename = "KSGF20180612_083109_V06.nc"

dtree = xd.io.open_cfradial1_datatree(filename)

dtree = rx.utils.combine_nexrad_sweeps(dtree)

dtree = dtree.xradar.map_over_sweeps(filter_radar)

dtree = dtree.xradar.georeference()
dtree.groups

('/',
 '/sweep_0',
 '/sweep_1',
 '/sweep_2',
 '/sweep_3',
 '/sweep_4',
 '/sweep_5',
 '/sweep_6',
 '/sweep_7',
 '/sweep_8',
 '/sweep_9',
 '/sweep_10',
 '/sweep_11',
 '/sweep_12',
 '/sweep_13',
 '/radar_parameters',
 '/georeferencing_correction',
 '/radar_calibration')

dtree["sweep_0"]["reflectivity"].plot(
    x="x",
    y="y",
    xlim=(-300e3, 200e3),
    ylim=(-200e3, 300e3),
    cmap="ChaseSpectral",
    levels=range(-10, 70),
)

<matplotlib.collections.QuadMesh at 0x7fce06aea600>

Radarx

tstart = datetime.now()
ds_rx = dtree.radarx.to_grid(
    data_vars=["reflectivity"],
    pseudo_cappi=False,
    x_lim=x_lims,
    y_lim=y_lims,
    z_lim=z_lims,
    x_step=h_res,
    y_step=h_res,
    z_step=v_res,
    x_smth=0.2,
    y_smth=0.2,
    z_smth=0.6,
)
print("Radarx gridding took:", datetime.now() - tstart)
display(ds_rx)

Radarx gridding took: 0:00:11.247278

<xarray.Dataset> Size: 9MB
Dimensions:       (z: 31, y: 276, x: 276)
Coordinates:
  * z             (z) float64 248B 0.0 500.0 1e+03 ... 1.4e+04 1.45e+04 1.5e+04
    lat           (y) float64 2kB 34.94 34.95 34.97 34.99 ... 39.87 39.88 39.9
    lon           (x) float64 2kB -96.68 -96.66 -96.64 ... -90.53 -90.5 -90.48
    latitude      float64 8B 37.24
    longitude     float64 8B -93.4
    altitude      float64 8B 419.0
    crs_wkt       int64 8B 0
  * x             (x) float64 2kB -3e+05 -2.98e+05 ... 2.48e+05 2.5e+05
  * y             (y) float64 2kB -2.5e+05 -2.48e+05 ... 2.98e+05 3e+05
Data variables:
    reflectivity  (z, y, x) float32 9MB nan nan nan nan nan ... nan nan nan nan
    time          datetime64[ns] 8B 2018-06-12T08:33:44.780257189
Attributes:
    Conventions:      CF/Radial instrument_parameters
    version:          1.3
    title:
    institution:
    references:
    source:
    comment:
    instrument_name:  KSGF
    history:
    radar_name:       KSGF

xarray.Dataset

• Dimensions:
  • z: 31
  • y: 276
  • x: 276
• Coordinates: (9)
  • z
    (z)
    float64
    0.0 500.0 ... 1.45e+04 1.5e+04

    array([    0.,   500.,  1000.,  1500.,  2000.,  2500.,  3000.,  3500.,  4000.,
            4500.,  5000.,  5500.,  6000.,  6500.,  7000.,  7500.,  8000.,  8500.,
            9000.,  9500., 10000., 10500., 11000., 11500., 12000., 12500., 13000.,
           13500., 14000., 14500., 15000.])

  • lat
    (y)
    float64
    34.94 34.95 34.97 ... 39.88 39.9

    array([34.936122, 34.954745, 34.973365, ..., 39.867412, 39.884851, 39.902285])

  • lon
    (x)
    float64
    -96.68 -96.66 ... -90.5 -90.48

    array([-96.683914, -96.662768, -96.641613, ..., -90.525743, -90.501643,
           -90.477531])

  • latitude
    ()
    float64
    37.24

    long_name :

    Latitude

    units :

    degrees_north

    standard_name :

    Latitude

    array(37.23523712)

  • longitude
    ()
    float64
    -93.4

    long_name :

    Longitude

    units :

    degrees_east

    standard_name :

    Longitude

    array(-93.40042114)

  • altitude
    ()
    float64
    419.0

    long_name :

    Altitude

    units :

    meters

    standard_name :

    Altitude

    positive :

    up

    array(419.)

  • crs_wkt
    ()
    int64
    0

    crs_wkt :

    PROJCRS["unknown",BASEGEOGCRS["unknown",DATUM["World Geodetic System 1984",ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1]],ID["EPSG",6326]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8901]]],CONVERSION["unknown",METHOD["Azimuthal Equidistant",ID["EPSG",1125]],PARAMETER["Latitude of natural origin",37.235237121582,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8801]],PARAMETER["Longitude of natural origin",-93.4004211425781,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8802]],PARAMETER["False easting",0,LENGTHUNIT["metre",1],ID["EPSG",8806]],PARAMETER["False northing",0,LENGTHUNIT["metre",1],ID["EPSG",8807]]],CS[Cartesian,2],AXIS["(E)",east,ORDER[1],LENGTHUNIT["metre",1,ID["EPSG",9001]]],AXIS["(N)",north,ORDER[2],LENGTHUNIT["metre",1,ID["EPSG",9001]]]]

    semi_major_axis :

    6378137.0

    semi_minor_axis :

    6356752.314245179

    inverse_flattening :

    298.257223563

    reference_ellipsoid_name :

    WGS 84

    longitude_of_prime_meridian :

    0.0

    prime_meridian_name :

    Greenwich

    geographic_crs_name :

    unknown

    horizontal_datum_name :

    World Geodetic System 1984

    projected_crs_name :

    unknown

    grid_mapping_name :

    azimuthal_equidistant

    latitude_of_projection_origin :

    37.235237121582

    longitude_of_projection_origin :

    -93.4004211425781

    false_easting :

    0.0

    false_northing :

    0.0

    array(0)

  • x
    (x)
    float64
    -3e+05 -2.98e+05 ... 2.5e+05

    array([-300000., -298000., -296000., ...,  246000.,  248000.,  250000.])

  • y
    (y)
    float64
    -2.5e+05 -2.48e+05 ... 3e+05

    array([-250000., -248000., -246000., ...,  296000.,  298000.,  300000.])

• Data variables: (2)
  • reflectivity
    (z, y, x)
    float32
    nan nan nan nan ... nan nan nan nan

    array([[[nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            ...,
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan]],
    
           [[nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            ...,
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan]],
    
           [[nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            ...,
    ...
            ...,
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan]],
    
           [[nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            ...,
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan]],
    
           [[nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            ...,
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan],
            [nan, nan, nan, ..., nan, nan, nan]]], dtype=float32)

  • time
    ()
    datetime64[ns]
    2018-06-12T08:33:44.780257189

    array('2018-06-12T08:33:44.780257189', dtype='datetime64[ns]')

• Indexes: (3)
  • z
    PandasIndex

    PandasIndex(Index([    0.0,   500.0,  1000.0,  1500.0,  2000.0,  2500.0,  3000.0,  3500.0,
            4000.0,  4500.0,  5000.0,  5500.0,  6000.0,  6500.0,  7000.0,  7500.0,
            8000.0,  8500.0,  9000.0,  9500.0, 10000.0, 10500.0, 11000.0, 11500.0,
           12000.0, 12500.0, 13000.0, 13500.0, 14000.0, 14500.0, 15000.0],
          dtype='float64', name='z'))

  • x
    PandasIndex

    PandasIndex(Index([-300000.0, -298000.0, -296000.0, -294000.0, -292000.0, -290000.0,
           -288000.0, -286000.0, -284000.0, -282000.0,
           ...
            232000.0,  234000.0,  236000.0,  238000.0,  240000.0,  242000.0,
            244000.0,  246000.0,  248000.0,  250000.0],
          dtype='float64', name='x', length=276))

  • y
    PandasIndex

    PandasIndex(Index([-250000.0, -248000.0, -246000.0, -244000.0, -242000.0, -240000.0,
           -238000.0, -236000.0, -234000.0, -232000.0,
           ...
            282000.0,  284000.0,  286000.0,  288000.0,  290000.0,  292000.0,
            294000.0,  296000.0,  298000.0,  300000.0],
          dtype='float64', name='y', length=276))

• Attributes: (10)

  Conventions :

  CF/Radial instrument_parameters

  version :

  1.3

  title :

  institution :

  references :

  source :

  comment :

  instrument_name :

  KSGF

  history :

  radar_name :

  KSGF

Plot

ds_rx.radarx.plot_max_cappi(
    data_var="reflectivity",
    vmin=-10,
    vmax=70,
    range_rings=True,
    add_map=True,
    projection=ccrs.PlateCarree(),
    title="Radarx",
)