/
viirs_sdr.py
664 lines (502 loc) · 21.9 KB
/
viirs_sdr.py
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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2011, 2012, 2013.
# Author(s):
#
# Adam Dybbroe <adam.dybbroe@smhi.se>
# Kristian Rune Larsen <krl@dmi.dk>
# Lars Ørum Rasmussen <ras@dmi.dk>
# Martin Raspaud <martin.raspaud@smhi.se>
#
# This file is part of mpop.
# mpop 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.
# mpop 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
# mpop. If not, see <http://www.gnu.org/licenses/>.
"""Interface to VIIRS SDR format
Format documentation:
http://npp.gsfc.nasa.gov/science/sciencedocuments/082012/474-00001-03_CDFCBVolIII_RevC.pdf
"""
import os.path
from ConfigParser import ConfigParser
from datetime import datetime, timedelta
import numpy as np
import h5py
import hashlib
from mpop import CONFIG_PATH
from mpop.satin.logger import LOG
from mpop.utils import strftime
NO_DATE = datetime(1958, 1, 1)
EPSILON_TIME = timedelta(days=2)
VIIRS_MBAND_GRANULE_SIZE = (768, 3200)
VIIRS_DNB_GRANULE_SIZE = (768, 4064)
VIIRS_IBAND_GRANULE_SIZE = (768*2, 3200*2)
VIIRS_IR_BANDS = ('M16', 'M15', 'M14', 'M13', 'M12', 'I5', 'I4')
VIIRS_VIS_BANDS = ('M1', 'M2', 'M3', 'M4', 'M5', 'M6',
'M7', 'M8', 'M9', 'M10', 'M11',
'I1', 'I2', 'I3')
VIIRS_DNB_BANDS = ('DNB', )
class HDF5MetaData(object):
"""
Small class for inspecting a HDF5 file and retrieve its metadata/header
data. It is developed for JPSS/NPP data but is really generic and should
work on most other hdf5 files.
Supports
"""
def __init__(self, filename):
self.metadata = {}
self.filename = filename
def read(self):
h5f = h5py.File(self.filename, 'r')
h5f.visititems(self.collect_metadata)
self._collect_attrs('/', h5f.attrs)
return self
def _collect_attrs(self, name, attrs):
for key, value in attrs.iteritems():
value = list(value[0])
if len(value) == 1:
self.metadata["%s/attr/%s" % (name, key)] = value[0]
else:
self.metadata["%s/attr/%s" % (name, key)] = value
def collect_metadata(self, name, obj):
if isinstance(obj, h5py.Dataset):
self.metadata["%s/shape" % name] = obj.shape
self._collect_attrs(name, obj.attrs)
def __getitem__(self, key):
long_key = None
for mkey in self.metadata.keys():
if mkey.endswith(key):
if long_key is not None:
raise KeyError("Multiple keys called %s" % key)
long_key = mkey
return self.metadata[long_key]
def keys(self):
return self.metadata.keys()
def get_data_keys(self):
data_keys = []
for key in self.metadata.keys():
if key.endswith("/shape"):
data_key = key.split("/shape")[0]
data_keys.append(data_key)
return data_keys
class NPPMetaData(HDF5MetaData):
def _parse_npp_datatime(self, datestr, timestr):
time_val = datetime.strptime(datestr + timestr, '%Y%m%d%H%M%S.%fZ')
if abs(time_val - NO_DATE) < EPSILON_TIME:
raise ValueError("Datetime invalid %s " % time_val)
return time_val
def get_begin_time(self):
return self._parse_npp_datatime(self['AggregateBeginningDate'],
self['AggregateBeginningTime'])
def get_end_time(self):
return self._parse_npp_datatime(self['AggregateEndingDate'],
self['AggregateEndingTime'])
def get_begin_orbit_number(self):
return int(self['AggregateBeginningOrbitNumber'])
def get_end_orbit_number(self):
return int(self['AggregateEndingOrbitNumber'])
def get_geofilname(self):
return self['N_GEO_Ref']
def get_shape(self):
shape = self['Radiance/shape']
band = self['Band_ID']
if band[0] == 'M':
if shape != VIIRS_MBAND_GRANULE_SIZE:
raise ValueError("Unsupported granule size %s for %s" % (shape, band))
elif band == "DNB":
if shape != VIIRS_DNB_GRANULE_SIZE:
raise ValueError("Unsupported granule size %s for %s" % (shape, band))
elif band[0] == "I":
if shape != VIIRS_IBAND_GRANULE_SIZE:
raise ValueError("Unsupported granule size %s for %s" % (shape, band))
return shape
def get_band_description(self):
band = self['Band_ID']
for band_desc in ('I', 'M', 'DNB', "N/A"):
if band.startswith(band_desc):
if band_desc == 'N/A':
return 'DNB'
return band_desc
return None
def _band_data_keys(self, data_type):
"""
:param data_type: Reflectance, Radiance or BrightnessTemperature
:type data_type: string
:returns: HDF5 data key and scale factor keys i a two element tuple
"""
data_key = None
factors_keys = None
for key in self.get_data_keys():
if key.endswith(data_type):
data_key = key
factors_keys = key+"Factors"
return (data_key, factors_keys)
def get_reflectance_keys(self):
return self._band_data_keys("Reflectance")
def get_radiance_keys(self):
return self._band_data_keys("Radiance")
def get_brightness_temperature_keys(self):
return self._band_data_keys("BrightnessTemperature")
def get_unit(self, calibrate = 1):
band = self['Band_ID']
if calibrate == 2 and band not in VIIRS_DNB_BANDS:
return "W m-2 um-1 sr-1"
if band in VIIRS_IR_BANDS:
return "K"
elif band in VIIRS_VIS_BANDS:
return '%'
elif band in VIIRS_DNB_BANDS:
return 'W m-2 sr-1'
return None
#
#
# http://yloiseau.dnsalias.net/articles/DesignPatterns/flyweight/
class GeolocationFlyweight(object):
def __init__(self, cls):
self._cls = cls
self._instances = dict()
def __call__(self, *args, **kargs):
"""
we assume that this is only used for the gelocation object,
filenames are listed in the second argument
"""
return self._instances.setdefault(tuple(args[1]),
self._cls(*args, **kargs))
def clear_cache(self):
del self._instances
@GeolocationFlyweight
class ViirsGeolocationData(object):
def __init__(self, shape, filenames):
self.filenames = filenames
self.longitudes = None
self.shape = shape
self.latitudes = None
def read(self):
"""
Read longitudes and latitudes from geo filenames and assemble
"""
if self.longitudes is not None:
return self
self.longitudes = np.ma.array(np.zeros(self.shape,
dtype=np.float32), fill_value=0)
self.latitudes = np.ma.array(np.zeros(self.shape,
dtype=np.float32), fill_value=0)
granule_length = self.shape[0]/len(self.filenames)
for index, filename in enumerate(self.filenames):
lon, lat = get_lonlat(filename)
swath_index = index * granule_length
y0_ = swath_index
y1_ = swath_index+granule_length
self.longitudes[y0_:y1_, :] = lon
self.latitudes[y0_:y1_, :] = lat
LOG.debug("Geolocation read in for... " + str(self))
return self
# ------------------------------------------------------------------------------
class ViirsBandData(object):
"""Placeholder for the VIIRS M&I-band data.
Reads the SDR data - one hdf5 file for each band.
Not yet considering the Day-Night Band
"""
def __init__(self, filenames, calibrate=1):
self.begin_time = 0
self.end_time = 0
self.orbit_begin = 0
self.orbit_end = 0
self.band_id = 'unknown'
self.data = None
self.scale = 1.0 # gain
self.offset = 0.0 # intercept
self.filenames = sorted(filenames)
self.units = 'unknown'
self.geo_filenames = []
self.calibrate = calibrate
self.data = None
self.geolocation = None
self.band_desc = None
self.band_uid = None
self.metadata = []
def read(self):
self._read_metadata()
LOG.debug("Shape of data: " + str(self.data.shape))
self._read_data()
return self
def _read_metadata(self):
for fname in self.filenames:
md = NPPMetaData(fname).read()
self.metadata.append(md)
self.geo_filenames.append(md.get_geofilname())
#
# initiate data arrays
granule_length, swath_width= self.metadata[0].get_shape()
shape = (granule_length * len(self.metadata), swath_width )
self.data = np.ma.array(np.zeros(shape, dtype=np.float32), fill_value=0)
self.orbit_begin = self.metadata[0].get_begin_orbit_number()
self.orbit_end = self.metadata[-1].get_end_orbit_number()
self.begin_time = self.metadata[0].get_begin_time()
self.end_time = self.metadata[-1].get_end_time()
self.unit = self.metadata[0].get_unit(self.calibrate)
self.band_desc = self.metadata[0].get_band_description()
self.band_id = self.metadata[0]['Band_ID']
if self.band_id == "N/A":
self.band_id = "DNB"
def _read_data(self):
"""Read one VIIRS M- or I-band channel: Data and attributes (meta data)
- *calibrate* set to 1 (default) returns reflectances for visual bands,
tb for ir bands, and radiance for dnb.
- *calibrate* set to 2 returns radiances.
"""
granule_length, swath_width= self.metadata[0].get_shape()
for index, md in enumerate(self.metadata):
h5f = h5py.File(md.filename, 'r')
# find appropiate band data to insert
data_key = None
factors_key = None
if self.calibrate == 1:
data_key, factors_key = md.get_reflectance_keys()
if data_key is None:
data_key, factors_key = md.get_brightness_temperature_keys()
# handle dnb data
if data_key is None and self.band_id == "DNB":
data_key, factors_key = md.get_radiance_keys()
elif self.calibrate == 2:
data_key, factors_key = md.get_radiance_keys()
#
# get granule data and scale and offset values
try:
granule_factors_data = h5f[factors_key].value
except KeyError:
#
# We can't find the factors this must be DNB
if self.band_id != "DNB":
raise
# The unit is W/sr cm-2 in the file! but we need 'W sr-1 m-2'
granule_factors_data = (10000., 0.)
granule_data = h5f[data_key].value
scale, offset = granule_factors_data[0:2]
# The VIIRS reflectances are between 0 and 1.
# mpop standard is '%'
if self.units == '%':
myscale = 100.0 # To get reflectances in percent!
else:
myscale = 1.0
# Masking spurious data
# according to documentation, mask integers >= 65328, floats <= -999.3
if issubclass(granule_data.dtype.type, np.integer):
band_mask = granule_data >= 65528
if issubclass(granule_data.dtype.type, np.floating):
band_mask = granule_data <= -999.2
# Is it necessary to mask negatives?
granule_data = granule_data.astype(np.float32)
granule_data *= self.scale
granule_data += self.offset
granule_data *= myscale
LOG.debug("dtype(granule_data) = " + str(granule_data.dtype))
band_mask |= granule_data < 0
masked_data = np.ma.array(granule_data, mask=band_mask, copy=False)
swath_index = index * granule_length
y0_ = swath_index
y1_ = swath_index+granule_length
self.data[y0_:y1_, :] = masked_data
self.band_uid = self.band_desc + hashlib.sha1(self.data.mask).hexdigest()
def read_lonlat(self, geofilepaths=None, geodir=None):
if geofilepaths is None:
if geodir is None:
geodir = os.path.dir(self.metadata[0].filename)
geofilepaths = [os.path.join(geodir, geofilepath)
for geofilepath in self.geo_filenames]
self.geolocation = ViirsGeolocationData(self.data.shape,
geofilepaths).read()
# ------------------------------------------------------------------------------
def get_lonlat(filename):
"""Read lon,lat from hdf5 file"""
LOG.debug("Geo File = " + filename)
md = HDF5MetaData(filename).read()
lats , lons = None, None
h5f = h5py.File(filename, 'r')
for key in md.get_data_keys():
if key.endswith("Latitude"):
lats = h5f[key].value
if key.endswith("Longitude"):
lons = h5f[key].value
return (np.ma.masked_less(lons, -999, False),
np.ma.masked_less(lats, -999, False))
def load(satscene, *args, **kwargs):
"""Read data from file and load it into *satscene*.
"""
conf = ConfigParser()
conf.read(os.path.join(CONFIG_PATH, satscene.fullname + ".cfg"))
options = {}
for option, value in conf.items(satscene.instrument_name+"-level2",
raw = True):
options[option] = value
CASES[satscene.instrument_name](satscene, options, *args, **kwargs)
def globify(filename):
filename = filename.replace("%Y", "????")
filename = filename.replace("%m", "??")
filename = filename.replace("%d", "??")
filename = filename.replace("%H", "??")
filename = filename.replace("%M", "??")
filename = filename.replace("%S", "??")
return filename
def _get_times_from_npp(filename):
bname = os.path.basename(filename)
sll = bname.split('_')
start_time = datetime.strptime(sll[2] + sll[3][:-1],
"d%Y%m%dt%H%M%S")
end_time = datetime.strptime(sll[2] + sll[4][:-1],
"d%Y%m%de%H%M%S")
if end_time < start_time:
end_time += timedelta(days=1)
return start_time, end_time
def _get_swathsegment(filelist, time_start, time_end=None):
"""
Return only the granule files for the time interval
"""
segment_files = []
for filename in filelist:
timetup = _get_times_from_npp(filename)
#Search for single granule using time start
if time_end is None:
if time_start >= timetup[0] and time_start <= timetup[1]:
segment_files.append(filename)
continue
# search for multiple granules
else:
# check that granule start time is inside interval
if timetup[0] >= time_start and timetup[0] <= time_end:
segment_files.append(filename)
continue
# check that granule end time is inside interval
if timetup[1] >= time_start and timetup[1] <= time_end:
segment_files.append(filename)
continue
segment_files.sort()
return segment_files
def load_viirs_sdr(satscene, options, *args, **kwargs):
"""Read viirs SDR reflectances and Tbs from file and load it into
*satscene*.
"""
calibrate = kwargs.get('calibrate', 1)
band_list = [ s.name for s in satscene.channels ]
chns = satscene.channels_to_load & set(band_list)
if len(chns) == 0:
return
if "time_interval" in kwargs:
time_start, time_end = kwargs['time_interval']
else:
time_start, time_end = satscene.time_slot, None
import glob
if "filename" not in options:
raise IOError("No filename given, cannot load")
values = {"orbit": satscene.orbit,
"satname": satscene.satname,
"instrument": satscene.instrument_name,
"satellite": satscene.satname
#"satellite": satscene.fullname
}
filename_tmpl = strftime(satscene.time_slot, options["filename"]) %values
directory = strftime(satscene.time_slot, options["dir"]) % values
if not os.path.exists(directory):
directory = globify(options["dir"]) % values
LOG.debug("Looking for files in directory " + str(directory))
directories = glob.glob(directory)
if len(directories) > 1:
raise IOError("More than one directory for npp scene... " +
"\nSearch path = %s\n\tPlease check npp.cfg file!" % directory)
elif len(directories) == 0:
raise IOError("No directory found for npp scene. " +
"\nSearch path = %s\n\tPlease check npp.cfg file!" % directory)
else:
directory = directories[0]
file_list = glob.glob(os.path.join(directory, filename_tmpl))
# Only take the files in the interval given:
LOG.debug("Number of files before segment selection: " + str(len(file_list)))
for fname in file_list:
if os.path.basename(fname).startswith("SVM14"):
LOG.debug("File before segmenting: " + os.path.basename(fname))
file_list = _get_swathsegment(file_list, time_start, time_end)
LOG.debug("Number of files after segment selection: " + str(len(file_list)))
for fname in file_list:
if os.path.basename(fname).startswith("SVM14"):
LOG.debug("File after segmenting: " + os.path.basename(fname))
filenames = [ os.path.basename(s) for s in file_list ]
LOG.debug("Template = " + str(filename_tmpl))
if len(file_list) % 22 != 0: # 22 VIIRS bands (16 M-bands + 5 I-bands + DNB)
LOG.warning("Number of SDR files is not divisible by 22!")
if len(file_list) == 0:
raise IOError("No VIIRS SDR file matching!: " +
os.path.join(directory, filename_tmpl))
geo_filenames_tmpl = strftime(satscene.time_slot,
options["geo_filenames"]) %values
geofile_list = glob.glob(os.path.join(directory, geo_filenames_tmpl))
# Only take the files in the interval given:
geofile_list = _get_swathsegment(geofile_list, time_start, time_end)
glob_info = {}
LOG.debug("Channels to load: " + str(satscene.channels_to_load))
for chn in satscene.channels_to_load:
# Take only those files in the list matching the band:
# (Filename starts with 'SV' and then the band-name)
fnames_band = []
try:
fnames_band = [ s for s in filenames if s.find('SV'+chn) >= 0 ]
except TypeError:
LOG.warning('Band frequency not available from VIIRS!')
LOG.info('Asking for channel' + str(chn) + '!')
if len(fnames_band) == 0:
continue
filename_band = [os.path.join(directory, fname) for fname in fnames_band]
LOG.debug("fnames_band = " + str(filename_band))
band = ViirsBandData(filename_band, calibrate=calibrate).read()
LOG.debug('Band id = ' + band.band_id)
band.read_lonlat(geodir=directory)
if not band.band_desc:
LOG.warning('Band name = ' + band.band_id)
raise AttributeError('Band description not supported!')
satscene[chn].data = band.data
satscene[chn].info['units'] = band.units
satscene[chn].info['band_id'] = band.band_id
# We assume the same geolocation should apply to all M-bands!
# ...and the same to all I-bands:
from pyresample import geometry
satscene[chn].area = geometry.SwathDefinition(
lons=np.ma.array(band.geolocation.longitudes, mask=band.data.mask,
copy=False),
lats=np.ma.array(band.geolocation.latitudes, mask=band.data.mask,
copy=False))
area_name = ("swath_" + satscene.fullname + "_" +
str(satscene.time_slot) + "_"
+ str(satscene[chn].data.shape) + "_" +
band.band_uid)
satscene[chn].area.area_id = area_name
satscene[chn].area_id = area_name
#except ImportError:
# satscene[chn].area = None
# satscene[chn].lat = np.ma.array(band.latitude, mask=band.data.mask)
# satscene[chn].lon = np.ma.array(band.longitude, mask=band.data.mask)
##if 'institution' not in glob_info:
## glob_info['institution'] = band.global_info['N_Dataset_Source']
##if 'mission_name' not in glob_info:
## glob_info['mission_name'] = band.global_info['Mission_Name']
ViirsGeolocationData.clear_cache()
# Compulsory global attribudes
satscene.info["title"] = (satscene.satname.capitalize() +
" satellite, " +
satscene.instrument_name.capitalize() +
" instrument.")
if 'institution' in glob_info:
satscene.info["institution"] = glob_info['institution']
if 'mission_name' in glob_info:
satscene.add_to_history(glob_info['mission_name'] +
" VIIRS SDR read by mpop")
else:
satscene.add_to_history("NPP/JPSS VIIRS SDR read by mpop")
satscene.info["references"] = "No reference."
satscene.info["comments"] = "No comment."
CASES = {
"viirs": load_viirs_sdr
}