Atmospheric Lidar Package: atmospheric_lidar/licel.py@97cabcc90f93 (annotated)

atmospheric_lidar/licel.py@97cabcc90f93 (annotated)

atmospheric_lidar/licel.py

Fri, 14 Feb 2020 12:38:45 +0200

author: Ioannis <ioannis@inoe.ro>
date: Fri, 14 Feb 2020 12:38:45 +0200
changeset 186: 97cabcc90f93
parent 182: a0bf7d88b1dc
child 189: e824878310ed
permissions: -rwxr-xr-x

Support of naming channels by order. In principle should not be required.

 import datetime
 import logging
 import copy
 import os
 import numpy as np
 import pytz
 from .generic import BaseLidarMeasurement, LidarChannel
 from .diva import DivaConverterMixin
 logger = logging.getLogger(__name__)
 c = 299792458.0  # Speed of light
 class LicelChannelData:
     """ A class representing a single channel found in a single Licel file."""
     def __init__(self, raw_info, raw_data, duration, use_id_as_name=False, channel_name=None):
         """
         This is run when creating a new object.
         Parameters
         ----------
         raw_info : dict
            A dictionary containing raw channel information.
         raw_data : dict
            An array with raw channel data.
         duration : float
            Duration of the file, in seconds
         use_id_as_name : bool
            If True, the transient digitizer name (e.g. BT0) is used as a channel
            name. If False, a more descriptive name is used (e.g. '01064.o_an').
         channel_name : str or None
            If provided, it will override the automatic generated channel name. It can be used if names are not unique.
         """
         self.raw_info = raw_info
         self.raw_data = raw_data
         self.duration = duration
         self.use_id_as_name = use_id_as_name
         self.channel_name_input = channel_name
         self._assign_properties()
     def _assign_properties(self):
         """ Assign properties """
         self.adcbits = int(self.raw_info['ADCbits'])
         self.active = int(self.raw_info['active'])
         self.analog_photon = self.raw_info['analog_photon']
         self.bin_width = float(self.raw_info['bin_width'])
         self.data_points = int(self.raw_info['number_of_datapoints'])
         self.hv = float(self.raw_info['HV'])
         self.id = self.raw_info['ID']
         self.laser_used = int(self.raw_info['laser_used'])
         self.number_of_shots = int(self.raw_info['number_of_shots'])
         self.wavelength_str = self.raw_info['wavelength']
         self.address = int(self.id[-1:], base=16)
         if self.is_analog:
             self.discriminator = float(self.raw_info['discriminator']) * 1000  # Analog range in mV
         else:
             self.discriminator = float(self.raw_info['discriminator'])
     @property
     def is_photodiode(self):
         return self.id[0:2] == 'PD'
     @property
     def wavelength(self):
         """ Property describing the nominal wavelength of the channel.
         Returns
         -------
         : int or None
            The integer value describing the wavelength. If no raw_info have been provided,
            returns None.
         """
         wavelength = self.wavelength_str.split('.')[0]
         return int(wavelength)
     @property
     def channel_name(self):
         """
         Construct the channel name adding analog photon info to avoid duplicates
         If use_id_as_name is True, the channel name will be the transient digitizer ID (e.g. BT01).
         This could be useful if the lidar system has multiple telescopes, so the descriptive name is
         not unique.
         Returns
         -------
         channel_name : str
            The channel name
         """
         if self.channel_name_input is not None:
             return self.channel_name_input
         if self.use_id_as_name:
             channel_name = self.id
         else:
             acquisition_type = self.analog_photon_string
             channel_name = "%s_%s" % (self.wavelength_str, acquisition_type)
         return channel_name
     @property
     def analog_photon_string(self):
         """ Convert the analog/photon flag found in the Licel file to a proper sting.
         Returns
         -------
         string : str
            'an' or 'ph' string, for analog or photon-counting channel respectively.
         """
         if self.analog_photon == '0':
             string = 'an'
         elif self.analog_photon == '1':
             string = 'ph'
         elif self.analog_photon == '2':
             string = 'std_an'
         elif self.analog_photon == '3':
             string = 'std_ph'
         else:
             string = str(self.analaog_photon)
         return string
     def calculate_physical(self):
         """ Calculate physically-meaningful data from raw channel data:
         * In case of analog signals, the data are converted to mV.
         * In case of photon counting signals, data are stored as number of photons.
         In addition, some ancillary variables are also calculated (z, dz, number_of_bins).
         """
         data = self.raw_data
         norm = data / float(self.number_of_shots)
         dz = self.bin_width
         if self.is_analog:
             # If the channel is in analog mode
             ADCrange = self.discriminator  # Discriminator value already in mV
             if self.is_photodiode and (self.adcbits == 0):
                 logger.info("Assuming adcbits equal 1. This is a bug in current licel format when storing photodiode data.")
                 channel_data = norm * ADCrange / (2 ** self.adcbits)
             else:
                 channel_data = norm * ADCrange / ((2 ** self.adcbits) - 1)  # Licel LabView code has a bug (does not account -1).
         else:
              channel_data = norm * self.number_of_shots
         # Calculate Z
         self.z = np.array([dz * bin_number + dz / 2.0 for bin_number in range(self.data_points)])
         self.dz = dz
         self.data = channel_data
     @property
     def is_analog(self):
         return self.analog_photon == '0'
 class LicelFile(object):
     """ A class representing a single binary Licel file. """
     licel_file_header_format = ['filename',
                                 'start_date start_time end_date end_time altitude longitude latitude zenith_angle',
                                 # Appart from Site that is read manually
                                 'LS1 rate_1 LS2 rate_2 number_of_datasets', ]
     licel_file_channel_format = 'active analog_photon laser_used number_of_datapoints 1 HV bin_width wavelength d1 d2 d3 d4 ADCbits number_of_shots discriminator ID'
     channel_data_class = LicelChannelData
     # If True, it corrects the old Raymetrics convention of zenith angle definition (zenith = -90 degrees)
     fix_zenith_angle = False
     def __init__(self, file_path, use_id_as_name=False, get_name_by_order=False, licel_timezone="UTC", import_now=True):
         """
         This is run when creating a new object.
         Parameters
         ----------
         file_path : str
            The path to the Licel file.
         use_id_as_name : bool
            If True, the transient digitizer name (e.g. BT0) is used as a channel
            name. If False, a more descriptive name is used (e.g. '01064.o_an').
         get_name_by_order : bool
            If True, the channel name is given by the order of the channel in the file. In this case the
            `use_id_as_name` variable is ignored.
         licel_timezone : str
            The timezone of dates found in the Licel files. Should match the available
            timezones in the TZ database.
         import_now : bool
            If True, the header and data are read immediately. If not, the user has to call the
            corresponding methods directly. This is used to speed up reading files when only
            header information are required.
         """
         self.file_path = file_path
         self.file_name = os.path.basename(file_path)
         self.use_id_as_name = use_id_as_name
         self.get_name_by_order = get_name_by_order
         self.start_time = None
         self.stop_time = None
         self.licel_timezone = licel_timezone
         if import_now:
             self.import_file()
         else:
             self.import_header_only()
     def import_file(self):
         """ Read the header info and data of the Licel file.
         """
         channels = {}
         photodiodes = {}
         with open(self.file_path, 'rb') as f:
             self.read_header(f)
             # Check the complete header is read
             f.readline()
             # Import the data
             for channel_no, current_channel_info in enumerate(self.channel_info):
                 raw_data = np.fromfile(f, 'i4', int(current_channel_info['number_of_datapoints']))
                 a = np.fromfile(f, 'b', 1)
                 b = np.fromfile(f, 'b', 1)
                 if (a[0] != 13) | (b[0] != 10):
                     logger.warning("No end of line found after record. File could be corrupt: %s" % self.file_path)
                     logger.warning('a: {0}, b: {1}.'.format(a, b))
                 if self.get_name_by_order:
                     channel_name = channel_no
                 else:
                     channel_name = None
                 channel = self.channel_data_class(current_channel_info, raw_data, self.duration(),
                                                   use_id_as_name=self.use_id_as_name, channel_name=channel_name)
                 # Assign the channel either as normal channel or photodiode
                 if channel.is_photodiode:
                     if channel.channel_name in photodiodes.keys():
                         # Check if current naming convention produces unique files
                         raise IOError('Trying to import two photodiodes with the same name')
                     photodiodes[channel.channel_name] = channel
                 else:
                     if channel.channel_name in channels.keys():
                         # Check if current naming convention does not produce unique files
                         raise IOError('Trying to import two channels with the same name')
                     channels[channel.channel_name] = channel
         self.channels = channels
         self.photodiodes = photodiodes
         self._calculate_physical()
     def read_header(self, f):
         """ Read the header of an open Licel file.
         Parameters
         ----------
         f : file-like object
            An open file object.
         """
         # Read the first 3 lines of the header
         raw_info = {}
         channel_info = []
         # Read first line
         raw_info['Filename'] = f.readline().decode().strip()
         raw_info.update(self._read_second_header_line(f))
         raw_info.update(self._read_rest_of_header(f))
         # Update the object properties based on the raw info
         start_string = '%s %s' % (raw_info['start_date'], raw_info['start_time'])
         stop_string = '%s %s' % (raw_info['end_date'], raw_info['end_time'])
         date_format = '%d/%m/%Y %H:%M:%S'
         try:
             logger.debug('Creating timezone object %s' % self.licel_timezone)
             timezone = pytz.timezone(self.licel_timezone)
         except:
             raise ValueError("Cloud not create time zone object %s" % self.licel_timezone)
         # According to pytz docs, timezones do not work with default datetime constructor.
         local_start_time = timezone.localize(datetime.datetime.strptime(start_string, date_format))
         local_stop_time = timezone.localize(datetime.datetime.strptime(stop_string, date_format))
         # Only save UTC time.
         self.start_time = local_start_time.astimezone(pytz.utc)
         self.stop_time = local_stop_time.astimezone(pytz.utc)
         # Read the rest of the header.
         for c1 in range(int(raw_info['number_of_datasets'])):
             channel_info.append(self.match_lines(f.readline().decode(), self.licel_file_channel_format))
         self.raw_info = raw_info
         self.channel_info = channel_info
         self._assign_properties()
     def _assign_properties(self):
         """ Assign properties from the raw_info dictionary. """
         self.number_of_datasets = int(self.raw_info['number_of_datasets'])
         self.altitude = float(self.raw_info['altitude'])
         self.longitude = float(self.raw_info['longitude'])
         self.latitude = float(self.raw_info['latitude'])
         self.zenith_angle_raw = float(self.raw_info['zenith_angle'])
         logger.debug('Fix zenith angle? %s' % self.fix_zenith_angle)
         if self.fix_zenith_angle:
             logger.debug('Fixing zenith angle.')
             self.zenith_angle = self._correct_zenith_angle(self.zenith_angle_raw)
         else:
             self.zenith_angle = self.zenith_angle_raw
     @staticmethod
     def _correct_zenith_angle(zenith_angle):
         """ Correct zenith angle from Raymetrics convention (zenith = -90 degrees).
         Parameters
         ----------
         zenith_angle : float
            Zenith angle in Raymetrics convention.
         Returns
         -------
         corrected_angle : float
            Corrected zenith angle.
         """
         corrected_angle = 90 + zenith_angle
         return corrected_angle
     def _read_second_header_line(self, f):
         """ Read the second line of a licel file. """
         raw_info = {}
         second_line = f.readline().decode()
         # Many Licel files don't follow the licel standard. Specifically, the
         # measurement site is not always 8 characters, and can include white
         # spaces. For this, the site name is detect everything before the first
         # date. For efficiency, the first date is found by the first '/'.
         # e.g. assuming a string like 'Site name 01/01/2010 ...'
         site_name = second_line.split('/')[0][:-2]
         clean_site_name = site_name.strip()
         raw_info['site'] = clean_site_name
         self.site = clean_site_name
         raw_info.update(self.match_lines(second_line[len(clean_site_name) + 1:], self.licel_file_header_format[1]))
         return raw_info
     def _read_rest_of_header(self, f):
         """ Read the rest of the header lines, after line 2. """
         # Read third line
         third_line = f.readline().decode()
         raw_dict = self.match_lines(third_line, self.licel_file_header_format[2])
         return raw_dict
     def _calculate_physical(self):
         """ Calculate physical quantities from raw data for all channels in the file. """
         for channel in self.channels.values():
             channel.calculate_physical()
         for photodiode in self.photodiodes.values():
             photodiode.calculate_physical()
     def duration(self):
         """ Return the duration of the file.
         Returns
         -------
         : float
            The duration of the file in seconds.
         """
         dt = self.stop_time - self.start_time
         return dt.seconds
     def import_header_only(self):
         """ Import only the header lines, without reading the actual data."""
         with open(self.file_path, 'rb') as f:
             self.read_header(f)
     @property
     def has_photodiode(self):
         return len(self.photodiodes) != 0
     @staticmethod
     def match_lines(f1, f2):
         list1 = f1.split()
         list2 = f2.split()
         if len(list1) != len(list2):
             logging.debug("Channel parameter list has different length from LICEL specifications.")
             logging.debug("List 1: %s" % list1)
             logging.debug("List 2: %s" % list2)
         combined = list(zip(list2, list1))
         combined = dict(combined)
         return combined
 class LicelChannel(LidarChannel):
     def __init__(self):
         self.name = None
         self.resolution = None
         self.points = None
         self.wavelength = None
         self.laser_used = None
         self.rc = []
         self.raw_info = []
         self.laser_shots = []
         self.duration = []
         self.discriminator = []
         self.hv = []
         self.data = {}
     def append_file(self, current_file, file_channel):
         """ Append file to the current object """
         self._assign_properties(current_file, file_channel)
         self.binwidth = self.resolution * 2. / c  # in seconds
         self.z = file_channel.z
         self.data[current_file.start_time] = file_channel.data
         self.raw_info.append(file_channel.raw_info)
         self.duration.append(file_channel.duration)
         self.laser_shots.append(file_channel.number_of_shots)
         self.discriminator.append(file_channel.discriminator)
         self.hv.append(file_channel.hv)
     @property
     def number_of_shots(self):
         """ Redundant, kept here for backward compatibility """
         return self.laser_shots
     def _assign_properties(self, current_file, file_channel):
         self._assign_unique_property('name', file_channel.channel_name)
         self._assign_unique_property('resolution', file_channel.dz)
         self._assign_unique_property('wavelength', file_channel.wavelength)
         self._assign_unique_property('points', file_channel.data_points)
         self._assign_unique_property('adcbits', file_channel.adcbits)
         self._assign_unique_property('active', file_channel.active)
         self._assign_unique_property('laser_used', file_channel.laser_used)
         self._assign_unique_property('analog_photon_string', file_channel.analog_photon_string)
         self._assign_unique_property('latitude', current_file.latitude)
         self._assign_unique_property('longitude', current_file.longitude)
     def _assign_unique_property(self, property_name, value):
         current_value = getattr(self, property_name, None)
         if current_value is None:
             setattr(self, property_name, value)
         else:
             if current_value != value:
                 raise ValueError('Cannot combine channels with different values of {0}.'.format(property_name))
     @property
     def is_analog(self):
         return self.analog_photon_string == 'an'
     @property
     def is_photon_counting(self):
         return self.analog_photon_string == 'ph'
     def __unicode__(self):
         return "<Licel channel: %s>" % self.name
     def __str__(self):
         return str(self).encode('utf-8')
 class PhotodiodeChannel(LicelChannel):
     def _assign_properties(self, current_channel, file_channel):
         """ In contrast with normal channels, don't check for constant points."""
         self._assign_unique_property('name', file_channel.channel_name)
         self._assign_unique_property('resolution', file_channel.dz)
         self._assign_unique_property('wavelength', file_channel.wavelength)
         self._assign_unique_property('adcbits', file_channel.adcbits)
         self._assign_unique_property('active', file_channel.active)
         self._assign_unique_property('laser_used', file_channel.laser_used)
         self._assign_unique_property('adcbits', file_channel.adcbits)
         self._assign_unique_property('analog_photon_string', file_channel.analog_photon_string)
 class LicelLidarMeasurement(BaseLidarMeasurement):
     file_class = LicelFile
     channel_class = LicelChannel
     photodiode_class = PhotodiodeChannel
     def __init__(self, file_list=None, use_id_as_name=False, get_name_by_order=False, licel_timezone='UTC'):
         self.raw_info = {}  # Keep the raw info from the files
         self.durations = {}  # Keep the duration of the files
         self.laser_shots = []
         self.use_id_as_name = use_id_as_name
         self.get_name_by_order = get_name_by_order
         self.licel_timezone = licel_timezone
         self.photodiodes = {}
         super(LicelLidarMeasurement, self).__init__(file_list)
     def _import_file(self, filename):
         if filename in self.files:
             logger.warning("File has been imported already: %s" % filename)
         else:
             logger.debug('Importing file {0}'.format(filename))
             current_file = self.file_class(filename, use_id_as_name=self.use_id_as_name,
                                            get_name_by_order=self.get_name_by_order,
                                            licel_timezone=self.licel_timezone)
             self.raw_info[current_file.file_path] = current_file.raw_info
             self.durations[current_file.file_path] = current_file.duration()
             file_laser_shots = []
             self._create_or_append_channel(current_file)
             self.laser_shots.append(file_laser_shots)
             self.files.append(current_file.file_path)
     def _create_or_append_channel(self, current_file):
         for channel_name, channel in current_file.channels.items():
             if channel_name not in self.channels:
                 self.channels[channel_name] = self.channel_class()
             self.channels[channel_name].append_file(current_file, channel)
         for photodiode_name, photodiode in current_file.photodiodes.items():
             if photodiode_name not in self.photodiodes:
                 self.photodiodes[photodiode_name] = self.photodiode_class()
             self.photodiodes[photodiode_name].append_file(current_file, photodiode)
     def append(self, other):
         self.start_times.extend(other.start_times)
         self.stop_times.extend(other.stop_times)
         for channel_name, channel in self.channels.items():
             channel.append(other.channels[channel_name])
     def _get_duration(self, raw_start_in_seconds):
         """ Return the duration for a given time scale. If only a single
         file is imported, then this cannot be guessed from the time difference
         and the raw_info of the file are checked.
         """
         if len(raw_start_in_seconds) == 1:  # If only one file imported
             duration = next(iter(self.durations.values()))  # Get the first (and only) raw_info
             duration_sec = duration
         else:
             duration_sec = np.diff(raw_start_in_seconds)[0]
         return duration_sec
     def _get_custom_variables(self, channel_names):
         daq_ranges = np.ma.masked_all(len(channel_names))
         for n, channel_name in enumerate(channel_names):
             channel = self.channels[channel_name]
             if channel.is_analog:
                 unique_values = list(set(channel.discriminator))
                 if len(unique_values) > 1:
                     logger.warning('More than one discriminator levels for channel {0}: {1}'.format(channel_name, unique_values))
                 daq_ranges[n] = unique_values[0]
         laser_shots = []
         for channel_name in channel_names:
             channel = self.channels[channel_name]
             laser_shots.append(channel.laser_shots)
         try:
             laser_shots = np.vstack(laser_shots).T
         except Exception as e:
             logger.error('Could not read laser shots as an array. Maybe files contain different number of channels?')
             raise e
         params = [{
             "name": "DAQ_Range",
             "dimensions": ('channels',),
             "type": 'd',
             "values": daq_ranges,
         }, {
             "name": "Laser_Shots",
             "dimensions": ('time', 'channels',),
             "type": 'i',
             "values": laser_shots,
         },
         ]
         return params
     def _get_custom_global_attributes(self):
         """
         NetCDF global attributes that should be included
         in the final NetCDF file.
         Currently the method assumes that all files in the measurement object have the same altitude, lat and lon
         properties.
         """
         logger.debug('Setting custom global attributes')
         logger.debug('raw_info keys: {0}'.format(self.raw_info.keys()))
         params = [{
             "name": "Altitude_meter_asl",
             "value": float(self.raw_info[self.files[0]]["altitude"])
         }, {
             "name": "Latitude_degrees_north",
             "value": float(self.raw_info[self.files[0]]["latitude"])
         }, {
             "name": "Longitude_degrees_east",
             "value": float(self.raw_info[self.files[0]]["longitude"])
         },
         ]
         return params
     def subset_by_channels(self, channel_subset):
         """
         Create a measurement object containing only a subset of  channels.
         This method overrides the parent method to add some licel-spefic parameters to the new object.
         Parameters
         ----------
         channel_subset : list
            A list of channel names (str) to be included in the new measurement object.
         Returns
         -------
         m : BaseLidarMeasurements object
            A new measurements object
         """
         new_measurement = super(LicelLidarMeasurement, self).subset_by_channels(channel_subset)
         new_measurement.raw_info = copy.deepcopy(self.raw_info)
         new_measurement.durations = copy.deepcopy(self.durations)
         new_measurement.laser_shots = copy.deepcopy(self.laser_shots)
         return new_measurement
     def subset_by_time(self, channel_subset):
         """
         Subsetting by time does not work yet with Licel files.
         This requires changes in generic.py
         """
         raise NotImplementedError("Subsetting by time, not yet implemented for Licel files.")
     def print_channels(self):
         """ Print the available channel information on the screen.
         """
         keys = sorted(self.channels.keys())
         print("Name  Wavelength  Mode  Resolution  Bins ")
         for key in keys:
             channel = self.channels[key]
             print("{0:<3}  {1:<10}  {2:<4}  {3:<10}  {4:<5}".format(channel.name, channel.wavelength,
                                                                     channel.analog_photon_string, channel.resolution,
                                                                     channel.points))
 class LicelDivaLidarMeasurement(DivaConverterMixin, LicelLidarMeasurement):
     pass

Mercurial > public > atmospheric_lidar / annotate

atmospheric_lidar/licel.py@97cabcc90f93 (annotated)

atmospheric_lidar/licel.py