satpy.readers.satpy_cf_nc module

Reader for files produced with the cf netcdf writer in satpy.

Introduction

The satpy_cf_nc reader reads data written by the satpy cf_writer. Filenames for cf_writer are optional. There are several readers using the same satpy_cf_nc.py reader.

  • Generic reader satpy_cf_nc

  • EUMETSAT GAC FDR reader avhrr_l1c_eum_gac_fdr_nc

Generic reader

The generic satpy_cf_nc reader reads files of type:

'{platform_name}-{sensor}-{start_time:%Y%m%d%H%M%S}-{end_time:%Y%m%d%H%M%S}.nc'

Example

Here is an example how to read the data in satpy:

from satpy import Scene

filenames = ['data/npp-viirs-mband-20201007075915-20201007080744.nc']
scn = Scene(reader='satpy_cf_nc', filenames=filenames)
scn.load(['M05'])
scn['M05']

Output:

<xarray.DataArray 'M05' (y: 4592, x: 3200)>
dask.array<open_dataset-d91cfbf1bf4f14710d27446d91cdc6e4M05, shape=(4592, 3200),
    dtype=float32, chunksize=(4096, 3200), chunktype=numpy.ndarray>
Coordinates:
    longitude  (y, x) float32 dask.array<chunksize=(4096, 3200), meta=np.ndarray>
    latitude   (y, x) float32 dask.array<chunksize=(4096, 3200), meta=np.ndarray>
Dimensions without coordinates: y, x
Attributes:
    start_time:                   2020-10-07 07:59:15
    start_orbit:                  46350
    end_time:                     2020-10-07 08:07:44
    end_orbit:                    46350
    calibration:                  reflectance
    long_name:                    M05
    modifiers:                    ('sunz_corrected',)
    platform_name:                Suomi-NPP
    resolution:                   742
    sensor:                       viirs
    standard_name:                toa_bidirectional_reflectance
    units:                        %
    wavelength:                   0.672 µm (0.662-0.682 µm)
    date_created:                 2020-10-07T08:20:02Z
    instrument:                   VIIRS

Notes

Available datasets and attributes will depend on the data saved with the cf_writer.

EUMETSAT AVHRR GAC FDR L1C reader

The avhrr_l1c_eum_gac_fdr_nc reader reads files of type:

''AVHRR-GAC_FDR_1C_{platform}_{start_time:%Y%m%dT%H%M%SZ}_{end_time:%Y%m%dT%H%M%SZ}_{processing_mode}_{disposition_mode}_{creation_time}_{version_int:04d}.nc'

Example

Here is an example how to read the data in satpy:

from satpy import Scene

filenames = ['data/AVHRR-GAC_FDR_1C_N06_19810330T042358Z_19810330T060903Z_R_O_20200101T000000Z_0100.nc']
scn = Scene(reader='avhrr_l1c_eum_gac_fdr_nc', filenames=filenames)
scn.load(['brightness_temperature_channel_4'])
scn['brightness_temperature_channel_4']

Output:

<xarray.DataArray 'brightness_temperature_channel_4' (y: 11, x: 409)>
dask.array<open_dataset-55ffbf3623b32077c67897f4283640a5brightness_temperature_channel_4, shape=(11, 409),
    dtype=float32, chunksize=(11, 409), chunktype=numpy.ndarray>
Coordinates:
  * x          (x) int16 0 1 2 3 4 5 6 7 8 ... 401 402 403 404 405 406 407 408
  * y          (y) int64 0 1 2 3 4 5 6 7 8 9 10
    acq_time   (y) datetime64[ns] dask.array<chunksize=(11,), meta=np.ndarray>
    longitude  (y, x) float64 dask.array<chunksize=(11, 409), meta=np.ndarray>
    latitude   (y, x) float64 dask.array<chunksize=(11, 409), meta=np.ndarray>
Attributes:
    start_time:                            1981-03-30 04:23:58
    end_time:                              1981-03-30 06:09:03
    calibration:                           brightness_temperature
    modifiers:                             ()
    resolution:                            1050
    standard_name:                         toa_brightness_temperature
    units:                                 K
    wavelength:                            10.8 µm (10.3-11.3 µm)
    Conventions:                           CF-1.8 ACDD-1.3
    comment:                               Developed in cooperation with EUME...
    creator_email:                         ops@eumetsat.int
    creator_name:                          EUMETSAT
    creator_url:                           https://www.eumetsat.int/
    date_created:                          2020-09-14T10:50:51.073707
    disposition_mode:                      O
    gac_filename:                          NSS.GHRR.NA.D81089.S0423.E0609.B09...
    geospatial_lat_max:                    89.95386902434623
    geospatial_lat_min:                    -89.97581969005503
    geospatial_lat_resolution:             1050 meters
    geospatial_lat_units:                  degrees_north
    geospatial_lon_max:                    179.99952992568998
    geospatial_lon_min:                    -180.0
    geospatial_lon_resolution:             1050 meters
    geospatial_lon_units:                  degrees_east
    ground_station:                        GC
    id:                                    DOI:10.5676/EUM/AVHRR_GAC_L1C_FDR/...
    institution:                           EUMETSAT
    instrument:                            Earth Remote Sensing Instruments >...
    keywords:                              ATMOSPHERE > ATMOSPHERIC RADIATION...
    keywords_vocabulary:                   GCMD Science Keywords, Version 9.1
    licence:                               EUMETSAT data policy https://www.e...
    naming_authority:                      int.eumetsat
    orbit_number_end:                      9123
    orbit_number_start:                    9122
    orbital_parameters_tle:                ['1 11416U 79057A   81090.16350942...
    platform:                              Earth Observation Satellites > NOA...
    processing_level:                      1C
    processing_mode:                       R
    product_version:                       1.0.0
    references:                            Devasthale, A., M. Raspaud, C. Sch...
    source:                                AVHRR GAC Level 1 Data
    standard_name_vocabulary:              CF Standard Name Table v73
    summary:                               Fundamental Data Record (FDR) of m...
    sun_earth_distance_correction_factor:  0.9975244779999585
    time_coverage_end:                     19820803T003900Z
    time_coverage_start:                   19800101T000000Z
    title:                                 AVHRR GAC L1C FDR
    version_calib_coeffs:                  PATMOS-x, v2017r1
    version_pygac:                         1.4.0
    version_pygac_fdr:                     0.1.dev107+gceb7b26.d20200910
    version_satpy:                         0.21.1.dev894+g5cf76e6
    history:                               Created by pytroll/satpy on 2020-0...
    name:                                  brightness_temperature_channel_4
    _satpy_id:                             DataID(name='brightness_temperatur...
    ancillary_variables:                   []
class satpy.readers.satpy_cf_nc.SatpyCFFileHandler(filename, filename_info, filetype_info, numeric_name_prefix='CHANNEL_')[source]

Bases: satpy.readers.file_handlers.BaseFileHandler

File handler for Satpy’s CF netCDF files.

Initialize file handler.

available_datasets(configured_datasets=None)[source]

Add information of available datasets.

property end_time

Get end time.

fix_modifier_attr(ds_info)[source]

Fix modifiers attribute.

get_dataset(ds_id, ds_info)[source]

Get dataset.

property sensor

Get sensor.

property sensor_names

Get sensor set.

property start_time

Get start time.