Atmospheric Lidar Package: licel.py@b1146c96f727 (annotated)

licel.py@b1146c96f727 (annotated)

licel.py

Mon, 22 Feb 2016 16:50:03 +0200

author: Ioannis <devnull@localhost>
date: Mon, 22 Feb 2016 16:50:03 +0200
changeset 35: b1146c96f727
parent 33: 2984158468e6
permissions: -rwxr-xr-x

Moving in separate folder.

 import numpy as np
 import datetime
 from generic import BaseLidarMeasurement, LidarChannel
 import musa_netcdf_parameters
 import musa_2009_netcdf_parameters
 licel_file_header_format = ['Filename',
                             'StartDate StartTime EndDate EndTime Altitude Longtitude Latitude ZenithAngle',  # Appart from Site that is read manually
                             'LS1 Rate1 LS2 Rate2 DataSets', ]
 licel_file_channel_format = 'Active AnalogPhoton LaserUsed DataPoints 1 HV BinW Wavelength d1 d2 d3 d4 ADCbits NShots Discriminator ID'
 class LicelFile:
     def __init__(self, filename):
         self.start_time = None
         self.stop_time = None
         self.import_file(filename)
         self.calculate_physical()
         self.filename = filename
     def calculate_physical(self):
         for channel in self.channels.itervalues():
             channel.calculate_physical()
     def import_file(self, filename):
         """Imports a licel file.
         Input: filename
         Output: object """
         channels = {}
         with open(filename, 'rb') as f:
             self.read_header(f)
             # Check the complete header is read
             a = f.readline()
             # Import the data
             for current_channel_info in self.channel_info:
                 raw_data = np.fromfile(f, 'i4', int(current_channel_info['DataPoints']))
                 a = np.fromfile(f, 'b', 1)
                 b = np.fromfile(f, 'b', 1)
                 if (a[0] != 13) | (b[0] != 10):
                     print "Warning: No end of line found after record. File could be corrupt"
                 channel = LicelFileChannel(current_channel_info, raw_data, self.duration())
                 channel_name = channel.channel_name
                 if channel_name in channels.keys():
                     # If the analog/photon naming scheme is not enough, find a new one!
                     raise IOError('Trying to import two channels with the same name')
                 channels[channel_name] = channel
         self.channels = channels
     def read_header(self, f):
         """ Read the header of a open file f.
         Returns raw_info and channel_info. Updates some object properties. """
         #Read the first 3 lines of the header
         raw_info = {}
         channel_info = []
         # Read first line
         raw_info['Filename'] = f.readline().strip()
         # Read second line
         second_line = f.readline()
         # 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
         raw_info.update(match_lines(second_line[len(clean_site_name) + 1:], licel_file_header_format[1]))
         # Read third line
         third_line = f.readline()
         raw_info.update(match_lines(third_line, licel_file_header_format[2]))
         # Update the object properties based on the raw info
         start_string = '%s %s' % (raw_info['StartDate'], raw_info['StartTime'])
         stop_string = '%s %s' % (raw_info['EndDate'], raw_info['EndTime'])
         date_format = '%d/%m/%Y %H:%M:%S'
         self.start_time = datetime.datetime.strptime(start_string, date_format)
         self.stop_time = datetime.datetime.strptime(stop_string, date_format)
         self.latitude = float(raw_info['Latitude'])
         self.longitude = float(raw_info['Longtitude'])
         # Read the rest of the header.
         for c1 in range(int(raw_info['DataSets'])):
             channel_info.append(match_lines(f.readline(), licel_file_channel_format))
         self.raw_info = raw_info
         self.channel_info = channel_info
     def duration(self):
         """ Return the duration of the file. """
         dt = self.stop_time - self.start_time
         return dt.seconds
 class LicelFileChannel:
     def __init__(self, raw_info = None, raw_data = None, duration = None):
         self.raw_info = raw_info
         self.raw_data = raw_data
         self.duration = duration
     @property
     def wavelength(self):
         if self.raw_info is not None:
             wave_str = self.raw_info['Wavelength']
             wavelength = wave_str.split('.')[0]
             return int(wavelength)
         else:
             return None
     @property
     def channel_name(self):
         '''
         Construct the channel name adding analog photon info to avoid duplicates
         '''
         acquisition_type = self.analog_photon_string(self.raw_info['AnalogPhoton'])
         channel_name = "%s_%s" % (self.raw_info['Wavelength'], acquisition_type)
         return channel_name
     def analog_photon_string(self, analog_photon_number):
         if analog_photon_number == '0':
             string = 'an'
         else:
             string = 'ph'
         return string
     def calculate_physical(self):
         data = self.raw_data
         number_of_shots = float(self.raw_info['NShots'])
         norm = data / number_of_shots
         dz = float(self.raw_info['BinW'])
         if self.raw_info['AnalogPhoton']=='0':
             # If the channel is in analog mode
             ADCb = int(self.raw_info['ADCbits'])
             ADCrange = float(self.raw_info['Discriminator'])*1000 # Value in mV
             channel_data = norm*ADCrange/((2**ADCb)-1)
             # print ADCb, ADCRange,cdata,norm
         else:
             # If the channel is in photoncounting mode
             # Frequency deduced from range resolution! (is this ok?)
             # c = 300 # The result will be in MHZ
             # SR  = c/(2*dz) # To account for pulse folding
             # channel_data = norm*SR
             # CHANGE:
             # For the SCC the data are needed in photons
             channel_data = norm *number_of_shots
             #print res,c,cdata,norm
         #Calculate Z
         number_of_bins  = int(self.raw_info['DataPoints'])
         self.z = np.array([dz*bin_number + dz/2.0 for bin_number in range(number_of_bins)])
         self.dz = dz
         self.number_of_bins = number_of_bins
         self.data = channel_data
 class LicelLidarMeasurement(BaseLidarMeasurement):
     '''
     '''
     extra_netcdf_parameters = musa_netcdf_parameters
     raw_info = {}   # Keep the raw info from the files
     durations = {}  # Keep the duration of the files
     def import_file(self, filename):
         if filename in self.files:
             print "File has been imported already:" + filename
         else:
             current_file = LicelFile(filename)
             self.raw_info[current_file.filename] = current_file.raw_info
             self.durations[current_file.filename] = current_file.duration()
             for channel_name, channel in current_file.channels.items():
                 if channel_name not in self.channels:
                     self.channels[channel_name] = LicelChannel(channel)
                 self.channels[channel_name].data[current_file.start_time] = channel.data
             self.files.append(current_file.filename)
     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 = self.durations.itervalues().next() # Get the first (and only) raw_info
             duration_sec = duration
         else:
             duration_sec = np.diff(raw_start_in_seconds)[0]
         return duration_sec
 class LicelChannel(LidarChannel):
     def __init__(self, channel_file):
         c = 299792458.0  # Speed of light
         self.wavelength = channel_file.wavelength
         self.name = channel_file.channel_name
         self.binwidth = channel_file.dz * 2 / c  # in seconds
         self.data = {}
         self.resolution = channel_file.dz
         self.z = np.arange(channel_file.number_of_bins) * self.resolution + self.resolution/2.0 #Change: add half bin in the z
         self.points = channel_file.number_of_bins
         self.rc = []
         self.duration  = channel_file.duration
     def append(self, other):
         if self.info != other.info:
             raise ValueError('Channel info are different. Data can not be combined.')
         self.data = np.vstack([self.data, other.data])
     def __unicode__(self):
         return "<Licel channel: %s>" % self.name
     def __str__(self):
         return unicode(self).encode('utf-8')
 class Licel2009LidarMeasurement(LicelLidarMeasurement):
     extra_netcdf_parameters = musa_2009_netcdf_parameters
 def match_lines(f1,f2):
     list1 = f1.split()
     list2 = f2.split()
     if len(list1) != len(list2):
         print "Warning: Combining lists of different lengths."
         print "List 1: %s" % list1
         print "List 2: %s" % list2
     combined = zip(list2,list1)
     combined = dict(combined)
     return combined

Mercurial > public > atmospheric_lidar / annotate

licel.py@b1146c96f727 (annotated)

licel.py