--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/atmospheric_lidar/diva.py Thu Dec 14 22:47:33 2017 +0200
@@ -0,0 +1,171 @@
+""" This is a class for experimenting with the new DIVA / EARLINET NetCDF file format.
+
+In the long run, this should be places as a method in BaseLidarMeasurement class. For now it is kept
+separately not to interfere with normal development.
+"""
+import netCDF4 as netcdf
+import pyyaml
+import datetime
+import os
+
+from .generic import BaseLidarMeasurement
+
+
+class DivaOutput(BaseLidarMeasurement):
+
+ def save_as_diva(self, output_path, parameter_file):
+ """ Save the current data in the 'draft' DIVA format. """
+
+ with open(parameter_file, 'r') as f:
+ parameters = pyyaml.load(f)
+
+ global_parameters = parameters['global_parameters'] # Shortcut
+
+ iso_date = datetime.datetime.utcnow().isoformat()
+ python_file_name = os.path.basename(__file__)
+
+ with netcdf.Dataset(output_path, 'w', format="NETCDF4") as f:
+
+ # Global attributes
+ f.title = global_parameters['title']
+ f.source = global_parameters['source']
+ f.institution = global_parameters['institution']
+ f.references = global_parameters['references']
+ f.location = global_parameters['location']
+ f.data_version = global_parameters['data_version']
+ f.conversion_date = iso_date
+ f.comment = global_parameters['comment']
+ f.Conventions = global_parameters['Conventions']
+ f.history = global_parameters['history'].format(date=iso_date, file=python_file_name)
+ f.featureType = "timeSeriesProfile"
+
+ # Top level variables
+ latitude = f.createVariable('latitude', datatype='f4')
+ latitude.standard_name = 'latitude'
+ latitude.long_name = 'system latitude'
+ latitude.units = 'degrees_north'
+
+ longitude = f.createVariable('longitude', datatype='f4')
+ longitude.standard_name = 'longitude'
+ longitude.long_name = 'system longitude'
+ longitude.units = 'degrees_east'
+
+ laser_angle = f.createVariable('laser_zenith_angle', datatype='f4')
+ laser_angle.standard_name = 'sensor_zenith_angle'
+ laser_angle.long_name = 'zenith angle of emitted laser'
+ laser_angle.units = 'degree'
+
+ laser_angle = f.createVariable('laser_zenith_angle', datatype='f4')
+ laser_angle.long_name = 'zenith angle of emitted laser'
+ laser_angle.units = 'degrees'
+
+ altitude = f.createVariable('altitude', datatype='f4')
+ altitude.standard_name = 'altitude'
+ altitude.long_name = 'system altitude'
+ altitude.units = 'm'
+
+
+ # Create a separate group for each channel
+ f = f.createGroup("channel_532nmP") # This should be changed to a meaningful channel name
+ f.data_type = self.data_type
+
+ f.createDimension('profile', len(self.time))
+ f.createDimension('range', len(self.range))
+
+ id = f.createVariable('channel_id', 'i4')
+ id.cf_role = "trajectory_id"
+
+ latitude = f.createVariable('latitude', datatype='f8', dimensions=('profile',), zlib=True)
+ latitude.long_name = 'aircraft GPS latitude'
+ latitude.units = 'degrees_north'
+ latitude.standard_name = 'latitude'
+
+ longitude = f.createVariable('longitude', datatype='f8', dimensions=('profile',), zlib=True)
+ longitude.long_name = 'aircraft GPS longitude'
+ longitude.units = 'degrees_east'
+ longitude.standard_name = 'longitude'
+
+ altitude = f.createVariable('altitude', datatype='f4', dimensions=('profile',), zlib=True)
+ altitude.long_name = 'aircraft GPS altitude'
+ altitude.units = 'm'
+ altitude.standard_name = 'altitude'
+
+ time = f.createVariable('time', datatype='f8', dimensions=('profile',),
+ zlib=True)
+ time.long_name = 'starting time of record'
+ time.units = "seconds since 1970-01-01 00:00:00"
+ time.standard_name = "time"
+
+ bin_range = f.createVariable('range', datatype='f4', dimensions=('range',),
+ zlib=True) # Use name 'bin_range' to avoid conflict with built-in range
+ bin_range.long_name = 'range from instrument'
+ bin_range.units = "m"
+ bin_range.positive = "down"
+ bin_range.axis = 'Z' # This is strictly not correct, as it does not correspond to geophysical variable. Still it can be usefull for quick plotting.
+
+ pitch = f.createVariable('pitch', datatype='f4', dimensions=('profile',), zlib=True)
+ pitch.long_name = 'aircraft pitch'
+ pitch.units = 'degree'
+ pitch.standard_name = 'platform_pitch_angle'
+ pitch.coordinates = "time longitude latitude"
+
+ roll = f.createVariable('roll', datatype='f4', dimensions=('profile',), zlib=True)
+ roll.long_name = 'aircraft roll'
+ roll.units = 'degree'
+ roll.standard_name = 'platform_roll_angle'
+ roll.coordinates = "time longitude latitude"
+
+ heading = f.createVariable('heading', datatype='f4', dimensions=('profile',), zlib=True)
+ heading.long_name = 'aircraft heading'
+ heading.units = 'degree'
+ heading.standard_name = 'platform_course'
+ heading.coordinates = "time longitude latitude"
+
+ hv = f.createVariable('hv', datatype='f4', dimensions=('profile',), zlib=True)
+ hv.long_name = 'detector high voltage'
+ hv.units = 'V'
+ hv.coordinates = "time longitude latitude"
+
+ averaging_time = f.createVariable('averaging_time', datatype='f4', dimensions=('profile',), zlib=True)
+ averaging_time.long_name = 'averaging time'
+ averaging_time.units = 's'
+ averaging_time.coordinates = "time longitude latitude"
+
+ emission_wl = f.createVariable('emission_wavelength', datatype='f8', dimensions=('profile',),
+ zlib=True)
+ emission_wl.long_name = 'emission wavelength in vacuum'
+ emission_wl.units = 'nm'
+ emission_wl.standard_name = 'radiation_wavelength'
+ emission_wl.coordinates = "time longitude latitude"
+
+ pulses = f.createVariable('pulses', datatype='i4', dimensions=('profile',),
+ zlib=True)
+ pulses.long_name = 'laser pulses per record'
+ pulses.coordinates = "time longitude latitude"
+
+ signal = f.createVariable('signal', datatype='i4', dimensions=('profile', 'range'),
+ zlib=True)
+ signal.long_name = 'signal'
+ signal.units = "counts"
+ signal.missing_value = -1
+ signal.coordinates = "time longitude latitude range"
+
+ # Assign channel attributes
+ f.channel_name = 'L_532nmP'
+
+ # Assign variables
+ id[:] = 1
+ latitude[:] = self.latitude[:]
+ longitude[:] = self.longitude[:]
+ altitude[:] = self.gps_altitude[:]
+ pitch[:] = self.pitch[:]
+ roll[:] = self.roll[:]
+ heading[:] = self.heading_angle[:]
+ hv[:] = self.high_voltage[:]
+ averaging_time[:] = self.averaging_time[:]
+ emission_wl[:] = self.emission_wavelength_vacuum[:]
+ pulses[:] = self.pulses[:]
+ time[:] = self.time[:]
+ bin_range[:] = self.range[:]
+ signal[:] = self.signal[:]
+
