#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2019 Satpy developers
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# satpy. If not, see <http://www.gnu.org/licenses/>.
"""VIIRS Active Fires reader.
This module implements readers for VIIRS Active Fires NetCDF and
ASCII files.
"""
import dask.dataframe as dd
import xarray as xr
from satpy.readers.file_handlers import BaseFileHandler
from satpy.readers.netcdf_utils import NetCDF4FileHandler
# map platform attributes to Oscar standard name
PLATFORM_MAP = {
"NPP": "Suomi-NPP",
"J01": "NOAA-20",
"J02": "NOAA-21"
}
[docs]
class VIIRSActiveFiresFileHandler(NetCDF4FileHandler):
"""NetCDF4 reader for VIIRS Active Fires."""
def __init__(self, filename, filename_info, filetype_info,
auto_maskandscale=False, xarray_kwargs=None):
"""Open and perform initial investigation of NetCDF file."""
super(VIIRSActiveFiresFileHandler, self).__init__(
filename, filename_info, filetype_info,
auto_maskandscale=auto_maskandscale, xarray_kwargs=xarray_kwargs)
self.prefix = filetype_info.get('variable_prefix')
[docs]
def get_dataset(self, dsid, dsinfo):
"""Get requested data as DataArray.
Args:
dsid: Dataset ID
param2: Dataset Information
Returns:
Dask DataArray: Data
"""
key = dsinfo.get('file_key', dsid['name']).format(variable_prefix=self.prefix)
data = self[key]
# rename "phoney dims"
data = data.rename(dict(zip(data.dims, ['y', 'x'])))
# handle attributes from YAML
for key in ('units', 'standard_name', 'flag_meanings', 'flag_values', '_FillValue'):
# we only want to add information that isn't present already
if key in dsinfo and key not in data.attrs:
data.attrs[key] = dsinfo[key]
if isinstance(data.attrs.get('flag_meanings'), str):
data.attrs['flag_meanings'] = data.attrs['flag_meanings'].split(' ')
# use more common CF standard units
if data.attrs.get('units') == 'kelvins':
data.attrs['units'] = 'K'
data.attrs["platform_name"] = PLATFORM_MAP.get(self.filename_info['satellite_name'].upper(), "unknown")
data.attrs["sensor"] = self.sensor_name
return data
@property
def start_time(self):
"""Get first date/time when observations were recorded."""
return self.filename_info['start_time']
@property
def end_time(self):
"""Get last date/time when observations were recorded."""
return self.filename_info.get('end_time', self.start_time)
@property
def sensor_name(self):
"""Name of sensor for this file."""
return self["/attr/instrument_name"].lower()
@property
def platform_name(self):
"""Name of platform/satellite for this file."""
return self["/attr/satellite_name"]
[docs]
class VIIRSActiveFiresTextFileHandler(BaseFileHandler):
"""ASCII reader for VIIRS Active Fires."""
def __init__(self, filename, filename_info, filetype_info):
"""Make sure filepath is valid and then reads data into a Dask DataFrame.
Args:
filename: Filename
filename_info: Filename information
filetype_info: Filetype information
"""
skip_rows = filetype_info.get('skip_rows', 15)
columns = filetype_info['columns']
self.file_content = dd.read_csv(filename, skiprows=skip_rows, header=None, names=columns)
super(VIIRSActiveFiresTextFileHandler, self).__init__(filename, filename_info, filetype_info)
self.platform_name = PLATFORM_MAP.get(self.filename_info['satellite_name'].upper(), "unknown")
[docs]
def get_dataset(self, dsid, dsinfo):
"""Get requested data as DataArray."""
ds = self[dsid['name']].to_dask_array(lengths=True)
data = xr.DataArray(ds, dims=("y",), attrs={"platform_name": self.platform_name, "sensor": "VIIRS"})
for key in ('units', 'standard_name', 'flag_meanings', 'flag_values', '_FillValue'):
# we only want to add information that isn't present already
if key in dsinfo and key not in data.attrs:
data.attrs[key] = dsinfo[key]
if isinstance(data.attrs.get('flag_meanings'), str):
data.attrs['flag_meanings'] = data.attrs['flag_meanings'].split(' ')
return data
@property
def start_time(self):
"""Get first date/time when observations were recorded."""
return self.filename_info['start_time']
@property
def end_time(self):
"""Get last date/time when observations were recorded."""
return self.filename_info.get('end_time', self.start_time)
def __getitem__(self, key):
"""Get file content for 'key'."""
return self.file_content[key]
def __contains__(self, item):
"""Check if variable is in current file."""
return item in self.file_content