satpy.readers.seviri_l1b_nc module

SEVIRI netcdf format reader.

class satpy.readers.seviri_l1b_nc.NCSEVIRIFileHandler(filename, filename_info, filetype_info, ext_calib_coefs=None, mask_bad_quality_scan_lines=True)[source]

Bases: BaseFileHandler

File handler for NC seviri files.

Calibration

See satpy.readers.seviri_base. Note that there is only one set of calibration coefficients available in the netCDF files and therefore there is no calib_mode argument.

Metadata

See satpy.readers.seviri_base.

Init the file handler.

_add_scanline_acq_time(dataset, dataset_id)[source]

_get_acq_time_hrv()[source]

_get_acq_time_visir(dataset_id)[source]

_get_calib_coefs(dataset, channel)[source]: Get coefficients for calibration from counts to radiance.

_get_earth_model()[source]

_mask_bad_quality(dataset, dataset_info)[source]: Mask scanlines with bad quality.

property _repeat_cycle_duration: Get repeat cycle duration from the metadata.

_update_attrs(dataset, dataset_info)[source]: Update dataset attributes.

calibrate(dataset, dataset_id)[source]: Calibrate the data.

property end_time: Get the general end time for this file.

get_area_def(dataset_id)[source]

Get the area def.

Note that the AreaDefinition area extents returned by this function for NetCDF data will be slightly different compared to the area extents returned by the SEVIRI HRIT reader. This is due to slightly different pixel size values when calculated using the data available in the files. E.g. for the 3 km grid:

NetCDF: self.nc.attrs['vis_ir_column_dir_grid_step'] == 3000.4031658172607 HRIT: np.deg2rad(2.**16 / pdict['lfac']) * pdict['h'] == 3000.4032785810186

This results in the Native 3 km full-disk area extents being approx. 20 cm shorter in each direction.

The method for calculating the area extents used by the HRIT reader (CFAC/LFAC mechanism) keeps the highest level of numeric precision and is used as reference by EUM. For this reason, the standard area definitions defined in the areas.yaml file correspond to the HRIT ones.

get_area_extent(dsid)[source]: Get the area extent.

get_dataset(dataset_id, dataset_info)[source]: Get the dataset.

get_metadata()[source]: Get metadata.

property nc: Read the file.

property nominal_end_time: Read the repeat cycle nominal end time from metadata and round it to expected nominal time slot.

property nominal_start_time: Read the repeat cycle nominal start time from metadata and round it to expected nominal time slot.

property observation_end_time: Get the repeat cycle observation end time from metadata.

property observation_start_time: Get the repeat cycle observation start time from metadata.

property satpos

Get actual satellite position in geodetic coordinates (WGS-84).

Evaluate orbit polynomials at the start time of the scan.

Returns: Longitude [deg east], Latitude [deg north] and Altitude [m]

property start_time: Get general start time for this file.

class satpy.readers.seviri_l1b_nc.NCSEVIRIHRVFileHandler(filename, filename_info, filetype_info, ext_calib_coefs=None, mask_bad_quality_scan_lines=True)[source]

Bases: NCSEVIRIFileHandler, SEVIRICalibrationHandler

HRV filehandler.

Init the file handler.

get_area_extent(dsid)[source]: Get HRV area extent.

get_dataset(dataset_id, dataset_info)[source]: Get dataset from file.