def l1_post_processing(self, l1_segments):
"""
Apply the post-processing procedures defined in the l1p processor definition file.
:param l1_segments: A list of Level-1 data objects
:return: None, the l1_segments are changed in place
"""
# Get the post processing options
pre_processing_items = self.cfg.get("pre_processing_items", None)
if pre_processing_items is None:
logger.info("No pre processing items defined")
return
# Measure time for the different post processors
timer = StopWatch()
# Get the list of post-processing items
for pp_item in pre_processing_items:
timer.start()
pp_class = get_cls(pp_item["module_name"],
pp_item["class_name"],
relaxed=False)
post_processor = pp_class(**pp_item["options"])
for l1 in l1_segments:
post_processor.apply(l1)
timer.stop()
msg = "- L1 pre-processing item `%s` applied in %.3f seconds" % (
pp_item["label"], timer.get_seconds())
logger.info(msg)
def get_l1(self, filepath, polar_ocean_check=None):
"""
Main entry point to the CryoSat-2 Baseline-D Input Adapter
:param filepath:
:return:
"""
timer = StopWatch()
timer.start()
# Save filepath
self.filepath = filepath
# Create an empty Level-1 data object
self.l1 = Level1bData()
# Input Validation
if not os.path.isfile(filepath):
msg = "Not a valid file: %s" % filepath
self.log.warning(msg)
self.error.add_error("invalid-filepath", msg)
return self.empty
# Parse the input file
self._read_input_netcdf(filepath, attributes_only=True)
if self.error.status:
return self.empty
# Get metadata
self._set_input_file_metadata()
if polar_ocean_check is not None:
has_polar_ocean_data = polar_ocean_check.has_polar_ocean_segments(
self.l1.info)
if not has_polar_ocean_data:
timer.stop()
return self.empty
# Polar ocean check passed, now fill the rest of the l1 data groups
self._set_l1_data_groups()
timer.stop()
self.log.info("- Created L1 object in %.3f seconds" %
timer.get_seconds())
# Return the l1 object
return self.l1
class Sentinel3CODAL2Wat(DefaultLoggingClass):
def __init__(self, cfg, raise_on_error=False):
"""
Input handler for Sentinel-3 L2WAT netCDF files from the CODA.
:param cfg: A treedict object (root.input_handler.options) from the corresponding Level-1 pre-processor
config file
:param raise_on_error: Boolean value if the class should raise an exception upon an error (default: False)
"""
cls_name = self.__class__.__name__
super(Sentinel3CODAL2Wat, self).__init__(cls_name)
self.error = ErrorStatus(caller_id=cls_name)
# Store arguments
self.raise_on_error = raise_on_error
self.cfg = cfg
# Init main class variables
self.nc = None
# Debug variables
self.timer = None
def get_l1(self, filepath, polar_ocean_check=None):
"""
Create a Level-1 data container from Sentinel-3 CODA L2WAT files
:param filepath: The full file path to the netCDF file
:param polar_ocean_check:
:return: The parsed (or empty) Level-1 data container
"""
# for debug purposes
self.timer = StopWatch()
self.timer.start()
# Save filepath
self.filepath = filepath
# Create an empty Level-1 data object
self.l1 = Level1bData()
# Input Validation
if not os.path.isfile(filepath):
msg = "Not a valid file: %s" % filepath
self.log.warning(msg)
self.error.add_error("invalid-filepath", msg)
return self.empty
# Parse xml header file
self._parse_xml_manifest(filepath)
# Parse the input netCDF file
self._read_input_netcdf(filepath)
if self.error.status:
return self.empty
# Get metadata
self._set_input_file_metadata()
# Test if input file contains data over polar oceans (optional)
if polar_ocean_check is not None:
has_polar_ocean_data = polar_ocean_check.has_polar_ocean_segments(
self.l1.info)
if not has_polar_ocean_data:
self.timer.stop()
return self.empty
# Polar ocean check passed, now fill the rest of the l1 data groups
self._set_l1_data_groups()
self.timer.stop()
self.log.info("- Created L1 object in %.3f seconds" %
self.timer.get_seconds())
# Return the l1 object
return self.l1
@staticmethod
def interp_1Hz_to_20Hz(variable_1Hz, time_1Hz, time_20Hz, **kwargs):
"""
Computes a simple linear interpolation to transform a 1Hz into a 20Hz variable
:param variable_1Hz: an 1Hz variable array
:param time_1Hz: 1Hz reference time
:param time_20Hz: 20 Hz reference time
:return: the interpolated 20Hz variable
"""
error_status = False
try:
f = interpolate.interp1d(time_1Hz,
variable_1Hz,
bounds_error=False,
**kwargs)
variable_20Hz = f(time_20Hz)
except ValueError:
fill_value = np.nan
variable_20Hz = np.full(time_20Hz.shape, fill_value)
error_status = True
return variable_20Hz, error_status
@staticmethod
def parse_sentinel3_l1b_xml_header(filename):
"""
Reads the XML header file of a Sentinel 3 L1b Data set
and returns the contents as an OrderedDict
"""
with open(filename) as fd:
content_odereddict = xmltodict.parse(fd.read())
return content_odereddict[u'xfdu:XFDU']
def _parse_xml_manifest(self, filepath):
"""
Parse the Sentinel-3 XML header file and extract key attributes for filtering
:param filepath: the filepath for the netcdf
:return: None
"""
# Retrieve header information from mission settings
xml_header_file = self.cfg.xml_manifest
dataset_folder = folder_from_filename(filepath)
filename_header = os.path.join(dataset_folder, xml_header_file)
self._xmlh = self.parse_sentinel3_l1b_xml_header(filename_header)
def _get_xml_content(self, section_name, tag):
""" Returns the generalProductInformation content of the xml manifest
:return: dictionary
"""
# Extract Metadata
metadata = self._xmlh["metadataSection"]["metadataObject"]
# Extract General Product Info
index = self.cfg.xml_metadata_object_index[section_name]
product_info = metadata[index]["metadataWrap"]["xmlData"]
product_info = product_info[tag]
return product_info
def _read_input_netcdf(self, filepath):
"""
Read the netCDF file via xarray
:param filepath: The full filepath to the netCDF file
:return: none
"""
try:
self.nc = xarray.open_dataset(filepath,
decode_times=False,
mask_and_scale=True)
except:
msg = "Error encountered by xarray parsing: %s" % filepath
self.error.add_error("xarray-parse-error", msg)
self.log.warning(msg)
return
def _set_input_file_metadata(self):
"""
Populates the product info segment of the Level1Data object with information from
the global attributes of the netCDF and content of the xml manifest
:return: None
"""
# Short cuts
metadata = self.nc.attrs
info = self.l1.info
# Get xml manifest content
product_info = self._get_xml_content(
"generalProductInformation", "sentinel3:generalProductInformation")
sral_info = self._get_xml_content("sralProductInformation",
"sralProductInformation")
# Processing environment metadata
info.set_attribute("pysiral_version", pysiral_version)
# General product metadata
mission = metadata["mission_name"].lower().replace(" ", "")
info.set_attribute("mission", str(mission))
info.set_attribute("mission_sensor", "sral")
info.set_attribute("mission_data_version", metadata["source"])
info.set_attribute("orbit", metadata["absolute_rev_number"])
info.set_attribute("cycle", metadata["cycle_number"])
info.set_attribute("mission_data_source", metadata["product_name"])
info.set_attribute(
"timeliness", self.cfg.timeliness_dict[str(
product_info["sentinel3:timeliness"])])
# Time-Orbit Metadata
lats = [
float(metadata["first_meas_lat"]),
float(metadata["last_meas_lat"])
]
lons = [
float(metadata["first_meas_lon"]),
float(metadata["last_meas_lon"])
]
info.set_attribute("start_time",
parse_datetime_str(metadata["first_meas_time"][4:]))
info.set_attribute("stop_time",
parse_datetime_str(metadata["last_meas_time"][4:]))
info.set_attribute("lat_min", np.amin(lats))
info.set_attribute("lat_max", np.amax(lats))
info.set_attribute("lon_min", np.amin(lons))
info.set_attribute("lon_max", np.amax(lons))
# Product Content Metadata
for mode in ["sar", "sin", "lrm"]:
percent_value = 0.0
if mode == "sar":
percent_value = 100.
info.set_attribute("{}_mode_percent".format(mode), percent_value)
info.set_attribute("open_ocean_percent",
float(sral_info["sral:openOceanPercentage"]))
def _set_l1_data_groups(self):
"""
Fill all data groups of the Level-1 data object with the content of the netCDF file. This is just the
overview method, see specific sub-methods below
:return: None
"""
self._set_time_orbit_data_group()
self._set_waveform_data_group()
self._set_range_correction_group()
self._set_surface_type_group()
self._set_classifier_group()
def _set_time_orbit_data_group(self):
"""
Transfer the time orbit parameter from the netcdf to l1 data object
:return: None
"""
# Transfer the timestamp
# NOTE: Here it is critical that the xarray does not automatically decodes time since it is
# difficult to work with the numpy datetime64 date format. Better to compute datetimes using
# a know num2date conversion
utc_timestamp = num2date(self.nc.time_20_ku.values,
units=self.nc.time_20_ku.units)
self.l1.time_orbit.timestamp = utc_timestamp
# Set the geolocation
self.l1.time_orbit.set_position(self.nc.lon_20_ku.values,
self.nc.lat_20_ku.values,
self.nc.alt_20_ku.values,
self.nc.orb_alt_rate_20_ku.values)
# Set antenna attitude
# NOTE: This are only available in 1Hz and need to be interpolated
time_01, time_20 = self.nc.time_01.values, self.nc.time_20_ku.values
pitch_angle_20, stat = self.interp_1Hz_to_20Hz(
self.nc.off_nadir_pitch_angle_pf_01.values, time_01, time_20)
roll_angle_20, stat = self.interp_1Hz_to_20Hz(
self.nc.off_nadir_roll_angle_pf_01.values, time_01, time_20)
yaw_angle_20, stat = self.interp_1Hz_to_20Hz(
self.nc.off_nadir_yaw_angle_pf_01.values, time_01, time_20)
self.l1.time_orbit.set_antenna_attitude(pitch_angle_20, roll_angle_20,
yaw_angle_20)
def _set_waveform_data_group(self):
"""
Transfer of the waveform group to the Level-1 object. This includes
1. the computation of waveform power in Watts
2. the computation of the window delay in meter for each waveform bin
3. extraction of the waveform valid flag
:return: None
"""
# Get the waveform
# NOTE: The waveform is given in counts
wfm_counts = self.nc.waveform_20_ku.values
n_records, n_range_bins = wfm_counts.shape
# Convert the waveform to power
# TODO: This needs to be verified. Currently using the scale factor and documentation in netcdf unclear
# From the documentation:
# "This scaling factor represents the backscatter coefficient for a waveform amplitude equal to 1.
# It is corrected for AGC instrumental errors (agc_cor_20_ku) and internal calibration (sig0_cal_20_ku)"
# NOTE: Make sure type of waveform is float and not double
# (double will cause issues with cythonized retrackers)
wfm_power = np.ndarray(shape=wfm_counts.shape, dtype=np.float32)
waveform_scale_factor = self.nc.scale_factor_20_ku.values
for record in np.arange(n_records):
wfm_power[record, :] = waveform_scale_factor[record] * wfm_counts[
record, :].astype(float)
# Get the window delay
# "The tracker_range_20hz is the range measured by the onboard tracker
# as the window delay, corrected for instrumental effects and
# CoG offset"
tracker_range_20hz = self.nc.tracker_range_20_ku.values
wfm_range = np.ndarray(shape=wfm_counts.shape, dtype=np.float32)
range_bin_index = np.arange(n_range_bins)
for record in np.arange(n_records):
wfm_range[record, :] = tracker_range_20hz[record] + \
(range_bin_index*self.cfg.range_bin_width) - \
(self.cfg.nominal_tracking_bin*self.cfg.range_bin_width)
# Set the operation mode
op_mode = self.nc.instr_op_mode_20_ku.values
op_mode_translator = self.cfg.instr_op_mode_list
radar_mode = np.array(
[op_mode_translator[int(val)] for val in op_mode]).astype("int8")
# Set the waveform
self.l1.waveform.set_waveform_data(wfm_power, wfm_range, radar_mode)
# Get the valid flags
# TODO: Find a way to get a valid flag
# measurement_confident_flag = self.nc.flag_mcd_20_ku.values
# valid_flag = measurement_confident_flag == 0
# self.l1.waveform.set_valid_flag(valid_flag)
def _set_range_correction_group(self):
"""
Transfer the range corrections defined in the l1p config file to the Level-1 object
NOTE: The range corrections are all in 1 Hz and must be interpolated to 20Hz
:return: None
"""
# Get the reference times for interpolating the range corrections from 1Hz -> 20Hz
time_1Hz = self.nc.time_01.values
time_20Hz = self.nc.time_20_ku.values
# Loop over all range correction variables defined in the processor definition file
for key in self.cfg.range_correction_targets.keys():
var_name = self.cfg.range_correction_targets[key]
variable_1Hz = getattr(self.nc, var_name)
variable_20Hz, error_status = self.interp_1Hz_to_20Hz(
variable_1Hz.values, time_1Hz, time_20Hz)
if error_status:
msg = "- Error in 20Hz interpolation for variable `%s` -> set only dummy" % var_name
self.log.warning(msg)
self.l1.correction.set_parameter(key, variable_20Hz)
def _set_surface_type_group(self):
"""
Transfer of the surface type flag to the Level-1 object
NOTE: In the current state (TEST dataset), the surface type flag is only 1 Hz. A nearest neighbour
interpolation is used to get the 20Hz surface type flag.
:return: None
"""
# Set the flag
for key in ESA_SURFACE_TYPE_DICT.keys():
flag = self.nc.surf_type_20_ku.values == ESA_SURFACE_TYPE_DICT[key]
self.l1.surface_type.add_flag(flag, key)
def _set_classifier_group(self):
"""
Transfer the classifiers defined in the l1p config file to the Level-1 object.
NOTE: It is assumed that all classifiers are 20Hz
In addition, a few legacy parameter are computed based on the waveform counts that is only available at
this stage. Computation of other parameter such as sigma_0, leading_edge_width, ... are moved to the
post-processing
:return: None
"""
# Loop over all classifier variables defined in the processor definition file
for key in self.cfg.classifier_targets.keys():
variable_20Hz = getattr(self.nc, self.cfg.classifier_targets[key])
self.l1.classifier.add(variable_20Hz, key)
@property
def empty(self):
"""
Default return object, if nodata should be returned
:return: Representation of an empty object (None)
"""
return None
class ERSReaperSGDR(DefaultLoggingClass):
""" Converts a Envisat SGDR object into a L1bData object """
def __init__(self, cfg, raise_on_error=False):
"""
Input handler for Sentinel-3 L2WAT netCDF files from the CODA.
:param cfg: A treedict object (root.input_handler.options) from the corresponding Level-1 pre-processor
config file
:param raise_on_error: Boolean value if the class should raise an exception upon an error (default: False)
"""
cls_name = self.__class__.__name__
super(ERSReaperSGDR, self).__init__(cls_name)
self.error = ErrorStatus(caller_id=cls_name)
# Store arguments
self.raise_on_error = raise_on_error
self.cfg = cfg
# Debug variables
self.timer = None
def get_l1(self, filepath, polar_ocean_check=None):
"""
Read the Envisat SGDR file and transfers its content to a Level1Data instance
:param filepath: The full file path to the netCDF file
:param polar_ocean_check: Mandatory parameter but will be ignored as ERS Data is full orbit
:return: The parsed (or empty) Level-1 data container
"""
# Store arguments
self.filepath = filepath
# Create an empty Level-1 data object
self.l1 = Level1bData()
# for debug purposes
self.timer = StopWatch()
self.timer.start()
# Read the file
# NOTE: This will create the variable `self.sgdr`
self._read_sgdr()
# Get metadata
self._set_input_file_metadata()
# Polar ocean check passed, now fill the rest of the l1 data groups
self._set_l1_data_groups()
self.timer.stop()
self.log.info("- Created L1 object in %.3f seconds" %
self.timer.get_seconds())
return self.l1
def _read_sgdr(self):
""" Read the L1b file and create a ERS native L1b object """
self.sgdr = ERSSGDR(self.cfg)
self.sgdr.filename = self.filepath
self.sgdr.parse()
error_status = self.sgdr.get_status()
if error_status:
# TODO: Needs ErrorHandler
raise IOError()
self.sgdr.post_processing()
def _set_input_file_metadata(self):
""" Extract essential metadata information from SGDR file """
info = self.l1.info
sgdr = self.sgdr
info.set_attribute("pysiral_version", psrlcfg.version)
try:
info.set_attribute(
"mission", self.cfg.platform_name_dict[str(sgdr.nc.mission)])
except KeyError:
mission_id = self.sgdr.guess_mission_from_filename()
info.set_attribute("mission",
self.cfg.platform_name_dict[str(mission_id)])
info.set_attribute("mission_data_version", sgdr.nc.software_ver)
info.set_attribute("orbit", sgdr.nc.abs_orbit)
info.set_attribute("cycle", sgdr.nc.cycle)
mission_data_source = Path(sgdr.nc.filename).name
info.set_attribute("mission_data_source", mission_data_source)
info.set_attribute("timeliness", self.cfg.timeliness)
def _set_l1_data_groups(self):
self._transfer_timeorbit() # (lon, lat, alt, time)
self._transfer_waveform_collection() # (power, range)
self._transfer_range_corrections() # (range corrections)
self._transfer_surface_type_data() # (land flag, ocean flag, ...)
self._transfer_classifiers() # (beam parameters, flags, ...)
def _transfer_timeorbit(self):
""" Extracts the time/orbit data group from the SGDR data """
# Transfer the orbit position
self.l1.time_orbit.set_position(self.sgdr.nc.lon_20hz.flatten(),
self.sgdr.nc.lat_20hz.flatten(),
self.sgdr.nc.alt_20hz.flatten())
# Transfer the timestamp
sgdr_timestamp = self.sgdr.nc.time_20hz.flatten()
units = self.cfg.sgdr_timestamp_units
calendar = self.cfg.sgdr_timestamp_calendar
timestamp = num2pydate(sgdr_timestamp, units, calendar)
self.l1.time_orbit.timestamp = timestamp
# Mandatory antenna pointing parameter (but not available for ERS)
dummy_angle = np.full(timestamp.shape, 0.0)
self.l1.time_orbit.set_antenna_attitude(dummy_angle, dummy_angle,
dummy_angle)
# Update meta data container
self.l1.update_data_limit_attributes()
def _transfer_waveform_collection(self):
""" Transfers the waveform data (power & range for each range bin) """
# Transfer the reformed 18Hz waveforms
self.l1.waveform.set_waveform_data(self.sgdr.wfm_power,
self.sgdr.wfm_range,
self.sgdr.radar_mode)
# Set valid flag to exclude calibration data
# (see section 3.5 of Reaper handbook)
tracking_state = self.sgdr.nc.alt_state_flag_20hz.flatten()
valid = ORCondition()
valid.add(tracking_state == 2)
valid.add(tracking_state == 3)
self.l1.waveform.set_valid_flag(valid.flag)
def _transfer_range_corrections(self):
"""
Transfer range correction data from the SGDR netCDF to the
l1bdata object. The parameter are defined in
config/mission_def.yaml for ers1/ers2
-> ersX.settings.sgdr_range_correction_targets
For a description of the parameter see section 3.10 in the
REAPER handbook
"""
grc_dict = self.cfg.range_correction_targets
for name in grc_dict.keys():
target_parameter = grc_dict[name]
if target_parameter is None:
continue
correction = getattr(self.sgdr.nc, target_parameter)
correction = np.repeat(correction, self.cfg.sgdr_n_blocks)
self.l1.correction.set_parameter(name, correction)
def _transfer_classifiers(self):
"""
Transfer classifier parameter from the SGDR netCDF to the
l1bdata object. Most parameter are defined in
config/mission_def.yaml for ers1/ers2
-> ersX.settings.sgdr_range_correction_targets
"""
target_dict = self.cfg.classifier_targets
for parameter_name in target_dict.keys():
nc_parameter_name = target_dict[parameter_name]
nc_parameter = getattr(self.sgdr.nc, nc_parameter_name)
self.l1.classifier.add(nc_parameter.flatten(), parameter_name)
def _transfer_surface_type_data(self):
surface_type = self.sgdr.nc.surface_type
surface_type = np.repeat(surface_type, self.cfg.sgdr_n_blocks)
for key in ESA_SURFACE_TYPE_DICT.keys():
flag = surface_type == ESA_SURFACE_TYPE_DICT[key]
self.l1.surface_type.add_flag(flag, key)
@property
def empty(self):
"""
Default return object, if nodata should be returned
:return: Representation of an empty object (None)
"""
return None
def get_l1(self, filepath, polar_ocean_check=None):
"""
Main entry point to the CryoSat-2 Baseline-D Input Adapter
:param filepath:
:param polar_ocean_check:
:return:
"""
timer = StopWatch()
timer.start()
# Save filepath
self.filepath = filepath
# Create an empty Level-1 data object
self.l1 = Level1bData()
# Input Validation
if not Path(filepath).is_file():
msg = "Not a valid file: %s" % filepath
logger.warning(msg)
self.error.add_error("invalid-filepath", msg)
return self.empty
# Parse the input file
self._read_input_netcdf(filepath, attributes_only=True)
if self.nc is None:
return self.empty
# CAVEAT: An issue has been identified with baseline-D L1b data when the orbit solution
# is based on predicted orbits and not the DORIS solution (Nov 2020).
# The source of the orbit data can be identified by the `vector_source` global attribute
# in the L1b source files. This can take/should take the following values:
#
# nrt: "fos predicted" (predicted orbit)
# "doris_navigator" (DORIS Nav solution)
#
# rep: "doris_precise" (final and precise DORIS solution)
#
# To prevent l1 data with erroneous orbit solution entering the processing chain, l1 data
# with the predicted orbit can be excluded here. The process of exclusion requires to set
# a flag in the l1 processor definition for the input handler:
#
# exclude_predicted_orbits: True
#
exclude_predicted_orbits = self.cfg.get("exclude_predicted_orbits",
False)
is_predicted_orbit = self.nc.vector_source.lower().strip(
) == "fos predicted"
logger.debug(self.nc.vector_source.lower().strip())
if is_predicted_orbit and exclude_predicted_orbits:
logger.warning("Predicted orbit solution detected -> skip file")
return self.empty
# Get metadata
self._set_input_file_metadata()
if polar_ocean_check is not None:
has_polar_ocean_data = polar_ocean_check.has_polar_ocean_segments(
self.l1.info)
if not has_polar_ocean_data:
timer.stop()
return self.empty
# Polar ocean check passed, now fill the rest of the l1 data groups
self._set_l1_data_groups()
timer.stop()
logger.info("- Created L1 object in %.3f seconds" %
timer.get_seconds())
# Return the l1 object
return self.l1
class EnvisatSGDRNC(DefaultLoggingClass):
""" Converts a Envisat SGDR object into a L1bData object """
def __init__(self, cfg, raise_on_error=False):
"""
Input handler for Sentinel-3 L2WAT netCDF files from the CODA.
:param cfg: A treedict object (root.input_handler.options) from the corresponding Level-1 pre-processor
config file
:param raise_on_error: Boolean value if the class should raise an exception upon an error (default: False)
"""
cls_name = self.__class__.__name__
super(EnvisatSGDRNC, self).__init__(cls_name)
self.error = ErrorStatus(caller_id=cls_name)
# Store arguments
self.raise_on_error = raise_on_error
self.cfg = cfg
# Debug variables
self.timer = None
# Properties
self.filepath = None
self.l1 = None
def get_l1(self, filepath, polar_ocean_check=None):
"""
Read the Envisat SGDR file and transfers its content to a Level1Data instance
:param filepath: The full file path to the netCDF file
:param polar_ocean_check: Mandatory parameter but will be ignored as ERS Data is full orbit
:return: The parsed (or empty) Level-1 data container
"""
# Store arguments
self.filepath = filepath
# Create an empty Level-1 data object
self.l1 = Level1bData()
# for debug purposes
self.timer = StopWatch()
self.timer.start()
# Read the file
# NOTE: This will create the variable `self.sgdr`
self._read_sgdr()
# Get metadata
self._set_input_file_metadata()
# Polar ocean check passed, now fill the rest of the l1 data groups
self._set_l1_data_groups()
self.timer.stop()
logger.info("- Created L1 object in %.3f seconds" % self.timer.get_seconds())
return self.l1
def _read_sgdr(self):
""" Read the L1b file and create a ERS native L1b object """
self.sgdr = ReadNC(self.filepath, nan_fill_value=True)
def _set_input_file_metadata(self):
""" Extract essential metadata information from SGDR file """
info = self.l1.info
sgdr = self.sgdr
info.set_attribute("pysiral_version", psrlcfg.version)
info.set_attribute("mission", "envisat")
info.set_attribute("mission_data_version", sgdr.software_version)
info.set_attribute("orbit", sgdr.absolute_orbit_number)
info.set_attribute("cycle", sgdr.cycle_number)
info.set_attribute("mission_data_source", sgdr.product_name)
info.set_attribute("timeliness", self.cfg.timeliness)
# # Time-Orbit Metadata
# lats = [float(sgdr.nc.ra0_first_lat), float(sgdr.nc.ra0_last_lat)]
# lons = [float(sgdr.nc.ra0_first_long), float(sgdr.nc.ra0_last_long)]
# info.set_attribute("start_time", parse_datetime_str(sgdr.nc.ra0_first_record_time))
# info.set_attribute("stop_time", parse_datetime_str(sgdr.nc.ra0_last_record_time))
# info.set_attribute("lat_min", np.amin(lats))
# info.set_attribute("lat_max", np.amax(lats))
# info.set_attribute("lon_min", np.amin(lons))
# info.set_attribute("lon_max", np.amax(lons))
def _set_l1_data_groups(self):
self._transfer_timeorbit() # (lon, lat, alt, time)
self._transfer_waveform_collection() # (power, range)
self._transfer_range_corrections() # (range corrections)
self._transfer_surface_type_data() # (land flag, ocean flag, ...)
self._transfer_classifiers() # (beam parameters, flags, ...)
def _transfer_timeorbit(self):
""" Extracts the time/orbit data group from the SGDR data """
# Transfer the orbit position
self.l1.time_orbit.set_position(self.sgdr.lon_20, self.sgdr.lat_20, self.sgdr.alt_20)
# Transfer the timestamp
sgdr_timestamp = self.sgdr.time_20
units = self.cfg.sgdr_timestamp_units
calendar = self.cfg.sgdr_timestamp_calendar
timestamp = num2pydate(sgdr_timestamp, units, calendar)
self.l1.time_orbit.timestamp = timestamp
# Mandatory antenna pointing parameter (but not available for ERS)
dummy_angle = np.full(timestamp.shape, 0.0)
self.l1.time_orbit.set_antenna_attitude(dummy_angle, dummy_angle, dummy_angle)
# Update meta data container
self.l1.update_data_limit_attributes()
def _transfer_waveform_collection(self):
""" Transfers the waveform data (power & range for each range bin) """
# Transfer the reformed 18Hz waveforms
# "waveform samples (I2+Q2, 1/2048 FFT power unit): 18 Hz Ku band";
# "the echo is corrected for the intermediate frequency filter effect";
wfm_power = self.sgdr.waveform_fft_20_ku
n_records, n_range_bins = wfm_power.shape
# Compute the window delay and the range values
window_delay_m = get_envisat_window_delay(
self.sgdr.tracker_range_20_ku,
self.sgdr.dop_cor_20_ku,
self.sgdr.dop_slope_cor_20_ku,
nominal_tracking_bin=self.cfg.nominal_tracking_bin,
bin_width_meter=self.cfg.bin_width_meter)
# Compute the range value for each range bin of the 18hz waveform
wfm_range = get_envisat_wfm_range(
window_delay_m, n_range_bins,
bin_width_meter=self.cfg.bin_width_meter)
# Transfer data to the waveform group
self.l1.waveform.set_waveform_data(wfm_power, wfm_range, self.cfg.radar_mode)
# Set valid flag to exclude calibration data
# (see section 3.5 of Reaper handbook)
valid_flag = np.logical_not(self.sgdr.waveform_fault_id_20.astype(bool))
self.l1.waveform.set_valid_flag(valid_flag)
def _transfer_range_corrections(self):
"""
Transfer range correction data from the SGDR netCDF to the
l1bdata object. The parameter are defined in
config/mission_def.yaml for ers1/ers2
-> ersX.settings.sgdr_range_correction_targets
For a description of the parameter see section 3.10 in the
REAPER handbook
"""
# Get the reference times for interpolating the range corrections from 1Hz -> 20Hz
time_1Hz = np.array(self.sgdr.time_01)
time_20Hz = np.array(self.sgdr.time_20)
# Loop over all range correction in config file
grc_dict = self.cfg.range_correction_targets
for name in grc_dict.keys():
# Get the variable
target_parameter = grc_dict[name]
if target_parameter is None:
continue
correction = np.array(getattr(self.sgdr, target_parameter))
# Debug code
# -> in this case discard the variable
n_nans = len(np.where(np.isnan(correction))[0])
if 500 < n_nans < len(correction):
msg = "Significant number of NaNs (%g) in range correction variable: %s"
msg = msg % (n_nans, target_parameter)
logger.warning(msg)
elif n_nans == len(correction):
msg = "All-NaN array encountered in range correction variable: %s"
msg = msg % target_parameter
logger.warning(msg)
# Some of the Envisat range corrections are 1Hz others 20Hz
# -> Those with "_01" in the variable name need to be
# extrapolated to 20 Hz
error = False
if re.search(self.cfg.variable_identifier_1Hz, target_parameter):
correction, error = self.interp_1Hz_to_20Hz(correction, time_1Hz, time_20Hz,
fill_on_error_value=0.0)
if error:
msg = "Failing to create 20Hz range correction variable for %s" % target_parameter
logger.warning(msg)
# Interpolate NaN's or return a zero-filled array for all-nan input variables
correction_filtered = self.find_and_interpolate_nans(correction, fill_on_error_value=0.0)
# Debug code
# -> in this case discard the variable
n_nans = len(np.where(np.isnan(correction_filtered))[0])
if n_nans > 0:
msg = "Remaining NaN's after filtering in %s" % target_parameter
logger.warning(msg)
# Set the parameter
self.l1.correction.set_parameter(name, correction_filtered)
def _transfer_classifiers(self):
"""
Transfer classifier parameter from the SGDR netCDF to the
l1bdata object. Most parameter are defined in
config/mission_def.yaml for ers1/ers2
-> ersX.settings.sgdr_range_correction_targets
"""
target_dict = self.cfg.classifier_targets
for parameter_name in target_dict.keys():
nc_parameter_name = target_dict[parameter_name]
nc_parameter = getattr(self.sgdr, nc_parameter_name)
self.l1.classifier.add(nc_parameter.flatten(), parameter_name)
def _transfer_surface_type_data(self):
surface_type = self.sgdr.surf_class_20
for key in ESA_SURFACE_TYPE_DICT.keys():
flag = surface_type == ESA_SURFACE_TYPE_DICT[key]
self.l1.surface_type.add_flag(flag, key)
@staticmethod
def find_and_interpolate_nans(variable, fill_on_error_value=np.nan):
"""
Replace NaN's in variable with linear interpolated values
:param variable:
:return: interpolated variable
"""
is_nan = np.isnan(variable)
n_nans = len(np.where(is_nan)[0])
if n_nans == 0:
variable_filtered = variable
else:
x = np.arange(len(variable))
valid = np.where(np.logical_not(is_nan))[0]
try:
f = interpolate.interp1d(x[valid], variable[valid], fill_value="extrapolate",
bounds_error=False)
variable_filtered = f(x)
except ValueError:
variable_filtered = np.full(variable.shape, fill_on_error_value)
return variable_filtered
@staticmethod
def interp_1Hz_to_20Hz(variable_1Hz, time_1Hz, time_20Hz, fill_on_error_value=np.nan, **kwargs):
"""
Computes a simple linear interpolation to transform a 1Hz into a 20Hz variable
:param variable_1Hz: an 1Hz variable array
:param time_1Hz: 1Hz reference time
:param time_20Hz: 20 Hz reference time
:return: the interpolated 20Hz variable
"""
error_status = False
try:
is_valid = np.logical_and(np.isfinite(time_1Hz), np.isfinite(variable_1Hz))
valid_indices = np.where(is_valid)[0]
f = interpolate.interp1d(time_1Hz[valid_indices], variable_1Hz[valid_indices],
fill_value="extrapolate", bounds_error=False, **kwargs)
variable_20Hz = f(time_20Hz)
except ValueError:
variable_20Hz = np.full(time_20Hz.shape, fill_on_error_value)
error_status = True
return variable_20Hz, error_status
@property
def empty(self):
"""
Default return object, if nodata should be returned
:return: Representation of an empty object (None)
"""
return None