def _apply_l1b_prefilter(self, l1b):
""" Apply filtering of l1b variables """
# Backward compatibility with older l2 setting files
if "l1b_pre_filtering" not in self.l2def:
return
# Apply filters
names, filters = self.l2def.l1b_pre_filtering.items()
for name, filter_def in zip(names, filters):
self.log.info("- Apply l1b pre-filter: %s" % filter_def.pyclass)
l1bfilter = get_filter(filter_def.pyclass)
l1bfilter.set_options(**filter_def.options)
l1bfilter.apply_filter(l1b)
def _apply_freeboard_filter(self, l2):
""" Apply freeboard filters as defined in the level-2 settings file
under `root.filter.freeboard`
Filtering means:
- setting the freeboard value to nan
- setting the surface type classification to invalid
"""
# Extract filters from settings structure
freeboard_filters = self.l2def.filter.freeboard
names, filters = td_branches(freeboard_filters)
# Loop over freeboard filters
for name, filter_def in zip(names, filters):
# Get corresponding class name in pysiral.filter and transfer options
# XXX: This should be rewritten as (e.g.)
# `frbfilter = VariableFilter(filter_def.pyclass, **filter_def.options)`
frbfilter = get_filter(filter_def.pyclass)
frbfilter.set_options(**filter_def.options)
# XXX: This is a temporary fix of an error in the algorithm
#
# Explanation: The filter target was wrongly set to radar freeboard,
# meaning that whether a freeboard value was filtered was determined on
# the wrong parameter. Both values differ by the geometric snow propagation
# correction (22% of snow depth). While the impact on the high freeboard end
# is negligible, at the lower (negative) end more freeboard where filtered
# than necessary since radar freeboard is always lower.
#
# The `afrb` filter target was hard coded, thus an option is added to replace
# the filter target (`root.filter.freeboard.frb_valid_range.filter_target`).
# The default option is the wrong one only for consistency reasons.
filter_target = "afrb"
if filter_def.options.has_key("filter_target"):
filter_target = filter_def.options.filter_target
# Check if action is required
frbfilter.apply_filter(l2, filter_target)
if frbfilter.flag.num == 0:
continue
# Logging
self.log.info("- Filter message: %s has flagged %g waveforms" % (
filter_def.pyclass, frbfilter.flag.num))
# Set surface type flag (contains invalid)
l2.surface_type.add_flag(frbfilter.flag.flag, "invalid")
# Remove invalid elevations / freeboards
l2.frb.set_nan_indices(frbfilter.flag.indices)
def _apply_thickness_filter(self, l2):
for name, filter_def in list(self.l2def.filter.thickness.items()):
sitfilter = get_filter(filter_def["pyclass"])
sitfilter.set_options(**filter_def["options"])
sitfilter.apply_filter(l2, "sit")
if sitfilter.flag.num == 0:
continue
self.log.info("- Filter message: %s has flagged %g waveforms" %
(filter_def["pyclass"], sitfilter.flag.num))
# Set surface type flag (contains invalid)
l2.surface_type.add_flag(sitfilter.flag.flag, "invalid")
# Remove invalid thickness values
l2.sit.set_nan_indices(sitfilter.flag.indices)
def _apply_thickness_filter(self, l2):
thickness_filters = self.l2def.filter.thickness
names, filters = td_branches(thickness_filters)
for name, filter_def in zip(names, filters):
sitfilter = get_filter(filter_def.pyclass)
sitfilter.set_options(**filter_def.options)
sitfilter.apply_filter(l2, "sit")
if sitfilter.flag.num == 0:
continue
self.log.info("- Filter message: %s has flagged %g waveforms" % (
filter_def.pyclass, sitfilter.flag.num))
# Set surface type flag (contains invalid)
l2.surface_type.add_flag(sitfilter.flag.flag, "invalid")
# Remove invalid thickness values
l2.sit.set_nan_indices(sitfilter.flag.indices)