Quick-view a vertical cut (RHI)

import datetime as dt

import matplotlib.pyplot as plt

Utility Functions

import radarpolarimetry as rp

Load Single Sweep

# choose radar specific parameters
start_time = dt.datetime(2017, 8, 10, 11, 0)
scan = "n_rhi_1"

swp = rp.load_single_sweep(
    start_time,
    scan,
    reindex_angle=dict(start_angle=0, stop_angle=90, direction=1.0, angle_res=0.25),
)
display(swp)

<xarray.Dataset> Size: 46MB
Dimensions:            (elevation: 360, range: 1333)
Coordinates: (12/15)
  * elevation          (elevation) float64 3kB 0.125 0.375 0.625 ... 89.62 89.88
    azimuth            (elevation) float64 3kB 256.0 256.0 256.0 ... 256.0 256.0
    time               (elevation) datetime64[ns] 3kB ...
  * range              (range) float32 5kB 37.5 112.5 ... 9.986e+04 9.994e+04
    x                  (elevation, range) float64 4MB -36.38 -109.2 ... -209.1
    y                  (elevation, range) float64 4MB -9.077 -27.23 ... -52.16
    ...                 ...
    bins               (elevation, range) float32 2MB 37.5 112.5 ... 9.994e+04
    sweep_mode         <U3 12B 'rhi'
    longitude          float64 8B 7.072
    latitude           float64 8B 50.73
    altitude           float64 8B 99.5
    crs_wkt            int64 8B 0
Data variables: (12/18)
    DBZH               (elevation, range) float32 2MB ...
    DBZV               (elevation, range) float32 2MB ...
    KDP                (elevation, range) float32 2MB ...
    RHOHV              (elevation, range) float32 2MB ...
    CMAP               (elevation, range) float32 2MB ...
    DBTH               (elevation, range) float32 2MB ...
    ...                 ...
    PHIDP              (elevation, range) float32 2MB ...
    sweep_number       int64 8B ...
    prt_mode           <U7 28B ...
    follow_mode        <U7 28B ...
    sweep_fixed_angle  float64 8B ...
    nyquist_velocity   float64 8B ...
Attributes:
    source:         gamic
    ant_gain_h:     44.0
    ant_gain_v:     44.0
    noise_power_h:  -0.52988
    noise_power_v:  -0.339564
    rx_loss_h:      0.73
    rx_loss_v:      0.73

xarray.Dataset

• Dimensions:
  • elevation: 360
  • range: 1333
• Coordinates: (15)
  • elevation
    (elevation)
    float64
    0.125 0.375 0.625 ... 89.62 89.88

    standard_name :

    ray_elevation_angle

    long_name :

    elevation_angle_from_horizontal_plane

    units :

    degrees

    axis :

    radial_elevation_coordinate

    array([ 0.125,  0.375,  0.625, ..., 89.375, 89.625, 89.875], shape=(360,))

  • azimuth
    (elevation)
    float64
    256.0 256.0 256.0 ... 256.0 256.0

    standard_name :

    ray_azimuth_angle

    long_name :

    azimuth_angle_from_true_north

    units :

    degrees

    axis :

    radial_azimuth_coordinate

    array([255.992432, 255.992432, 255.992432, ..., 255.992432, 255.992432,
           255.992432], shape=(360,))

  • time
    (elevation)
    datetime64[ns]
    ...

    standard_name :

    time

    [360 values with dtype=datetime64[ns]]

  • range
    (range)
    float32
    37.5 112.5 ... 9.986e+04 9.994e+04

    units :

    meters

    standard_name :

    projection_range_coordinate

    long_name :

    range_to_measurement_volume

    axis :

    radial_range_coordinate

    meters_between_gates :

    75.0

    spacing_is_constant :

    true

    meters_to_center_of_first_gate :

    37.5

    array([3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04, 9.98625e+04,
           9.99375e+04], shape=(1333,), dtype=float32)

  • x
    (elevation, range)
    float64
    -36.38 -109.2 ... -208.9 -209.1

    axis :

    X

    long_name :

    Easting

    standard_name :

    projection_x_coordinate

    units :

    metre

    array([[-3.63843776e+01, -1.09153131e+02, -1.81921881e+02, ...,
            -9.68118857e+04, -9.68846407e+04, -9.69573956e+04],
           [-3.63836842e+01, -1.09151046e+02, -1.81918400e+02, ...,
            -9.68050772e+04, -9.68778233e+04, -9.69505694e+04],
           [-3.63822981e+01, -1.09146884e+02, -1.81911455e+02, ...,
            -9.67964267e+04, -9.68691626e+04, -9.69418984e+04],
           ...,
           [-3.96883314e-01, -1.19063942e+00, -1.98438150e+00, ...,
            -1.04383912e+03, -1.04461454e+03, -1.04538995e+03],
           [-2.38133011e-01, -7.14392720e-01, -1.19064401e+00, ...,
            -6.26311145e+02, -6.26776404e+02, -6.27241656e+02],
           [-7.93781741e-02, -2.38132418e-01, -3.96883856e-01, ...,
            -2.08771661e+02, -2.08926748e+02, -2.09081833e+02]],
          shape=(360, 1333))

  • y
    (elevation, range)
    float64
    -9.077 -27.23 ... -52.12 -52.16

    axis :

    Y

    long_name :

    Northing

    standard_name :

    projection_y_coordinate

    units :

    metre

    array([[-9.07674924e+00, -2.72302472e+01, -4.53837445e+01, ...,
            -2.41514977e+04, -2.41696477e+04, -2.41877978e+04],
           [-9.07657626e+00, -2.72297272e+01, -4.53828761e+01, ...,
            -2.41497992e+04, -2.41679470e+04, -2.41860949e+04],
           [-9.07623047e+00, -2.72286888e+01, -4.53811436e+01, ...,
            -2.41476411e+04, -2.41657864e+04, -2.41839317e+04],
           ...,
           [-9.90098104e-02, -2.97026807e-01, -4.95040303e-01, ...,
            -2.60404782e+02, -2.60598226e+02, -2.60791666e+02],
           [-5.94066402e-02, -1.78218346e-01, -2.97027952e-01, ...,
            -1.56244784e+02, -1.56360851e+02, -1.56476917e+02],
           [-1.98023391e-02, -5.94064923e-02, -9.90099455e-02, ...,
            -5.20819137e+01, -5.21206031e+01, -5.21592918e+01]],
          shape=(360, 1333))

  • z
    (elevation, range)
    float64
    99.58 99.75 ... 9.996e+04 1e+05

    standard_name :

    height_above_ground

    units :

    metre

    array([[9.95818951e+01, 9.97461823e+01, 9.99111323e+01, ...,
            9.03782106e+02, 9.04827775e+02, 9.05874108e+02],
           [9.97455180e+01, 1.00237051e+02, 1.00729247e+02, ...,
            1.33913030e+03, 1.34050312e+03, 1.34187659e+03],
           [9.99091363e+01, 1.00727906e+02, 1.01547338e+02, ...,
            1.77444374e+03, 1.77614365e+03, 1.77784423e+03],
           ...,
           [1.36997769e+02, 2.11993307e+02, 2.86988845e+02, ...,
            9.98811321e+04, 9.99561278e+04, 1.00031123e+05],
           [1.36999197e+02, 2.11997590e+02, 2.86995984e+02, ...,
            9.98848875e+04, 9.99598860e+04, 1.00034884e+05],
           [1.36999911e+02, 2.11999732e+02, 2.86999554e+02, ...,
            9.98867653e+04, 9.99617651e+04, 1.00036765e+05]],
          shape=(360, 1333))

  • gr
    (elevation, range)
    float64
    13.63 88.63 163.6 ... 191.5 191.6

    standard_name :

    distance_from_radar

    units :

    metre

    array([[1.36265430e+01, 8.86254823e+01, 1.63624419e+02, ...,
            9.97550630e+04, 9.98300477e+04, 9.99050324e+04],
           [1.36258283e+01, 8.86233340e+01, 1.63620831e+02, ...,
            9.97480458e+04, 9.98230214e+04, 9.98979970e+04],
           [1.36243997e+01, 8.86190439e+01, 1.63613674e+02, ...,
            9.97391302e+04, 9.98140953e+04, 9.98890603e+04],
           ...,
           [2.34638810e+01, 2.26457981e+01, 2.18277298e+01, ...,
            1.05195733e+03, 1.05275652e+03, 1.05355570e+03],
           [2.36274966e+01, 2.31366407e+01, 2.26457934e+01, ...,
            6.21633139e+02, 6.22112658e+02, 6.22592168e+02],
           [2.37911169e+01, 2.36274972e+01, 2.34638804e+01, ...,
            1.91297079e+02, 1.91456920e+02, 1.91616758e+02]],
          shape=(360, 1333))

  • rays
    (elevation, range)
    float64
    0.125 0.125 0.125 ... 89.88 89.88

    standard_name :

    ray_elevation_angle

    long_name :

    elevation_angle_from_horizontal_plane

    units :

    degrees

    axis :

    radial_elevation_coordinate

    array([[ 0.125,  0.125,  0.125, ...,  0.125,  0.125,  0.125],
           [ 0.375,  0.375,  0.375, ...,  0.375,  0.375,  0.375],
           [ 0.625,  0.625,  0.625, ...,  0.625,  0.625,  0.625],
           ...,
           [89.375, 89.375, 89.375, ..., 89.375, 89.375, 89.375],
           [89.625, 89.625, 89.625, ..., 89.625, 89.625, 89.625],
           [89.875, 89.875, 89.875, ..., 89.875, 89.875, 89.875]],
          shape=(360, 1333))

  • bins
    (elevation, range)
    float32
    37.5 112.5 ... 9.986e+04 9.994e+04

    units :

    meters

    standard_name :

    projection_range_coordinate

    long_name :

    range_to_measurement_volume

    axis :

    radial_range_coordinate

    meters_between_gates :

    75.0

    spacing_is_constant :

    true

    meters_to_center_of_first_gate :

    37.5

    array([[3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04,
            9.98625e+04, 9.99375e+04],
           [3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04,
            9.98625e+04, 9.99375e+04],
           [3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04,
            9.98625e+04, 9.99375e+04],
           ...,
           [3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04,
            9.98625e+04, 9.99375e+04],
           [3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04,
            9.98625e+04, 9.99375e+04],
           [3.75000e+01, 1.12500e+02, 1.87500e+02, ..., 9.97875e+04,
            9.98625e+04, 9.99375e+04]], shape=(360, 1333), dtype=float32)

  • sweep_mode
    ()
    <U3
    'rhi'

    array('rhi', dtype='<U3')

  • longitude
    ()
    float64
    7.072

    long_name :

    longitude

    units :

    degrees_east

    standard_name :

    longitude

    array(7.071663)

  • latitude
    ()
    float64
    50.73

    long_name :

    latitude

    units :

    degrees_north

    positive :

    up

    standard_name :

    latitude

    array(50.73052)

  • altitude
    ()
    float64
    99.5

    long_name :

    altitude

    units :

    meters

    standard_name :

    altitude

    array(99.5)

  • crs_wkt
    ()
    int64
    0

    crs_wkt :

    PROJCRS["AEQD centered at 50.73052N 7.071663E",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",50.73052,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8801]],PARAMETER["Longitude of natural origin",7.071663,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 :

    AEQD centered at 50.73052N 7.071663E

    grid_mapping_name :

    azimuthal_equidistant

    latitude_of_projection_origin :

    50.73052

    longitude_of_projection_origin :

    7.071663

    false_easting :

    0.0

    false_northing :

    0.0

    array(0)

• Data variables: (18)
  • DBZH
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    dBZ

    long_name :

    Equivalent reflectivity factor H

    units :

    dBZ

    standard_name :

    radar_equivalent_reflectivity_factor_h

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • DBZV
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    dBZ

    long_name :

    Equivalent reflectivity factor V

    units :

    dBZ

    standard_name :

    radar_equivalent_reflectivity_factor_v

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • KDP
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    deg/km

    long_name :

    Specific differential phase HV

    units :

    degrees per kilometer

    standard_name :

    radar_specific_differential_phase_hv

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • RHOHV
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    long_name :

    Correlation coefficient HV

    units :

    unitless

    standard_name :

    radar_correlation_coefficient_hv

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • CMAP
    (elevation, range)
    float32
    ...

    format :

    UV16

    is_dft :

    0

    long_name :

    Clutter Map

    units :

    unitless

    standard_name :

    clutter_map

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • DBTH
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    dBZ

    long_name :

    Total power H (uncorrected reflectivity)

    units :

    dBZ

    standard_name :

    radar_equivalent_reflectivity_factor_h

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • DBTV
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    dBZ

    long_name :

    Total power V (uncorrected reflectivity)

    units :

    dBZ

    standard_name :

    radar_equivalent_reflectivity_factor_v

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • ZDR
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    dB

    long_name :

    Log differential reflectivity H/V

    units :

    dB

    standard_name :

    radar_differential_reflectivity_hv

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • VRADH
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    m/s

    long_name :

    Radial velocity of scatterers away from instrument H

    units :

    meters per seconds

    standard_name :

    radial_velocity_of_scatterers_away_from_instrument_h

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • VRADV
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    m/s

    long_name :

    Radial velocity of scatterers away from instrument V

    units :

    meters per second

    standard_name :

    radial_velocity_of_scatterers_away_from_instrument_v

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • WRADH
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    m/s

    long_name :

    Doppler spectrum width H

    units :

    meters per seconds

    standard_name :

    radar_doppler_spectrum_width_h

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • WRADV
    (elevation, range)
    float32
    ...

    format :

    UV8

    is_dft :

    0

    unit :

    m/s

    long_name :

    Doppler spectrum width V

    units :

    meters per second

    standard_name :

    radar_doppler_spectrum_width_v

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • PHIDP
    (elevation, range)
    float32
    ...

    format :

    UV16

    is_dft :

    0

    unit :

    deg

    long_name :

    Differential phase HV

    units :

    degrees

    standard_name :

    radar_differential_phase_hv

    _Undetect :

    0.0

    [479880 values with dtype=float32]

  • sweep_number
    ()
    int64
    ...

    [1 values with dtype=int64]

  • prt_mode
    ()
    <U7
    ...

    [1 values with dtype=<U7]

  • follow_mode
    ()
    <U7
    ...

    [1 values with dtype=<U7]

  • sweep_fixed_angle
    ()
    float64
    ...

    [1 values with dtype=float64]

  • nyquist_velocity
    ()
    float64
    ...

    standard_name :

    nyquist_velocity

    units :

    m s-1

    [1 values with dtype=float64]

• Attributes: (7)

  source :

  gamic

  ant_gain_h :

  44.0

  ant_gain_v :

  44.0

  noise_power_h :

  -0.52988

  noise_power_v :

  -0.339564

  rx_loss_h :

  0.73

  rx_loss_v :

  0.73

Plot reflectivity

The simplest Plot

pm = swp.DBZH.plot()
txt = plt.title("Simple Range-Elevation Plot")

Simplest RHI plot

Using xarray wrl.vis-accessor RHI plots can be created.

pm = swp.DBZH.wrl.vis.plot()
txt = plt.title("Simple RHI Plot")

Zooming in using matplotlib

pm = swp.DBZH.wrl.vis.plot()
txt = plt.title("Simple RHI Plot")
plt.gca().set_xlim(0, 60000)
plt.gca().set_ylim(0, 8000)

(0.0, 8000.0)

plot in curvelinear grid

fig = plt.figure(figsize=(10, 3))
proj = {"angular_spacing": 20.0, "radial_spacing": 20.0, "latmin": 1000}
pm = swp.DBZH.wrl.vis.plot(fig=fig, crs=proj)
txt = plt.title("Simple RHI Plot", y=1.05)
plt.gca().set_ylim(0, 8000)
plt.gca().set_xlim(0, 50000)

(0.0, 50000.0)