docs/file_formats/low_resolution.rst@0964f87e239a
docs/file_formats/low_resolution.rst
Sun, 26 Nov 2017 06:27:15 +0000
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- Ioannis Binietoglou <ulalume3@yahoo.com>
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Low Resolution SCC L1 Products ============================== .. warning:: This section is still under development. Introduction ------------ The Single Calculus Chain (SCC) is the standard EARLINET tool to perform automatic and quality nchecked analysis of raw lidar data. It is composed by three different modules: - ELPP (EARLINET Lidar Pre-Processor) - ELDA (EARLINET Lidar Data Analizer) - ELDEC (EARLINET Lidar DEpolarization Calibrator) Whenever an input file containing raw lidar data has been submitted to the SCC ELPP is automatically ran on it. The ELPP module pre-processes the raw data performing all the corrections and data handling needed before the optical retrieval algorithms can be applied by ELDA module. The ELPP output files contain pre-processed range corrected signals corrected for instrumental effects as well as atmospheric molecular parameters calculated from standard model or radiosounding. Typically, the vertical and temporal resolutions of the pre-processed signals included in these files is lower than the raw vertical and temporal resolution as in general time/vertical integration is performed by ELPP to increase the SNR and allow the calculation of optical products with a reduced uncertainties. As a consequence the ELPP output files are called Low Resolution SCC L1 Products. Another SCC module (HiRELPP – High Resolution EARLINET Lidar Pre-Processor) currently under development will produce High Resolution SCC L1 Products in which both time and vertical resolution are kept as higher as possible. This document provides a detailed description about the structure and the format of Low Resolution SCC L1 Product as produced by the SCC v4.0. Low Resolution SCC L1 Product: File format ------------------------------------------ The Low Resolution SCC L1 Products are files in Network Common Data Form (NetCDF) which is a well known self-describing, machine-independent data format that support the creation, access, and sharing of array-oriented scientific data. For more information about NetCDF format: http://www.unidata.ucar.edu/software/netcdf/. The NetCDF is a binary format that allows the definition of multi-dimensional variables of several types (integers, double, character, etc). For each variable it is possible to define one or more attributes where to specify variable properties like units, long name, description, etc. It is possible to define global attributes which are not related to a specific variable but to the whole file. A NetCDF file is composed by four different section: dimensions this section contains all the dimensions used in the definition of all the variables included in the NetCDF file variables this section contains all the variables stored in the NetCDF file. Each variable is defined as a multi-dimensional array of a specific type and with all the dimensions defined in the dimensions section global attributes this section lists all the attributes referring to the whole file. As the variable the attributes (global or the one attached to a specific variable) can be of different type data in this section the data contained in each variable defined in variable section is stored. Attribute values (both global or related to a specific variable) are not reported in data section but directly in variable or global attribute sections. Each Low Resolution SCC L1 Product correspond to a single emission wavelength. For example it is possible to find in the same file the elastic and the Raman channel pre-processed time-series corresponding to the same emission wavelength (but to a different detection wavelengths) but not two elastic time-series referring to different emission wavelengths. Low Resolution SCC L1 Product Format: dimensions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The following dimensions are defined in the Low Resolution SCC L1 Product: - time - points - channels - scan\_angles The dimension *time* specifies the number of RCS (for each channel) composing all the pre-processed time-series reported in the file. The dimension *points* represents the number of rangebins characterizing the pre-processed RCS. In case RCSs corresponding to different channels are characterized by different rangebins the dimension time is to the the maximum value of rangebins. The dimension *channels* indicates the number channels at which the RCS time-series included in the file refer to. The dimension *scan\_angles* takes into account how many zenith scan angles have been used to measure the RCS time-series reported into the file Low Resolution SCC L1 Product Format: variables ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In this section all the possible Low Resolution SCC L1 Product variables are reported. There are some variables that are mandatory and have to be present in all the Low Resolution SCC L1 Product files while there are others that have to be present only in specific cases. Technical Variables ################### altitude\_resolution :Type: *double* :Dimensions: *scan\_angles* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double altitude_resolution(scan_angles)`` This variable describes the altitude resolution corresponding to the RCS time-series reported in the file. It is needed to compute the vertical scale of the RCS corresponding to each scan angle which should be calculated as it follow: .. math:: H(\alpha, z)= \Delta h(\alpha)\left(z + \frac{1}{2}\right) where *z* is the altitude, :math:`\alpha` is the scan angle value and :math:`\Delta h` is the value reported by *altitude\_resolution* variable. range\_resolution :Type: *double* :Dimensions: *scan\_angles* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double range_resolution(scan_angles)`` This variable describes the range resolution corresponding to the RCS time-series reported in the file. It is needed to compute the range scale of the RCS corresponding to each scan angle which should be calculated as it follow: .. math:: R(\alpha, z)= \Delta r(\alpha)\left(r + \frac{1}{2}\right) where *r* is the range, :math:`\alpha` is the scan angle value and :math:`\Delta r` is the value reported by *range\_resolution* variable. Altitude and range resolution are the same if the scan angle is zero (zenith acquisition). laser\_pointing\_angle :Type: *double* :Dimensions: *scan\_angles* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double laser_pointing_angle(scan_angles)`` This variable provides the value of the zenith scan angles used during the measurement. The value of angle are in degrees with respect to the zenith direction. emission\_wavelength :Type: *double* :Dimensions: *channels* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double emission_wavelength(channels)`` This variable provides the value of the emission wavelength (in nm) corresponding to each RCS time-series. detection\_wavelength :Type: *double* :Dimensions: *channels* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double detection_wavelength(channels)`` This variable provides the value of the detection wavelength (in nm) corresponding to each RCS time-series. For elastic channels the detection and emission wavelength are the same or slightly different. laser\_pointing\_angle\_of\_profiles :Type: *integer* :Dimensions: *time* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``int laser_pointing_angle_of_profiles(time)`` This variable allows to identify the zenith angle at which each single RCS contained in the time-series refer to. In particular, for a given time the variable *laser\_pointing\_angle\_of\_profiles(time)* provides the scan angle index at which all the RCS included in the file refer to at the same time. To get the value of the scan angle the variable *laser\_pointing\_angle* should be evaluated in correspondence of the index returned by the variable *laser\_pointing\_angle\_of\_profiles(time)*. shots :Type: *integer* :Dimensions: *time* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``int shots(time)`` This variable report the number of laser shots that have been integrated the all the RCS time-series at a given time. start\_time :Type: *integer* :Dimensions: *time* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``int start_time(time)`` Variable reporting the value of the start time of each RCS within all the time-series in seconds since the start of measurement. stop\_time :Type: *integer* :Dimensions: *time* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``int stop_time(time)`` Variables reporting the value of the stop time of each RCS within all the time-series in seconds since the start of the measurement. LR\_Input :Type: *integer* :Dimensions: N/A :Location: Present only if the Low Resolution SCC L1 Product corresponds to an elastic only product :Definition: ``int LR_Input`` This variable is only used by ELDA module in the elastic only retrieval to know which value of particle lidar ratio assume in the retrieval. A value of 1 means to use a fixed value stored in the SCC database for each product. A value of 0 means to use a profile of lidar ratio provided by the user as external file. overlap\_correction :Type: *integer* :Dimensions: N/A :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``int overlap_correction`` This variable provides information on the overlap correction of all the RCS time-series included in the file. If it is set to 1 the overlap correction has been applied if it is set to null value the overlap correction has not been applied. cloud\_flag :Type: *integer* :Dimensions: *time, points* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``int cloud_flag(time, points)`` variable reporting the cloud mask on the RCS time-series included in the file. A value of 1 means no cloud any other values different from 1 correspond to the presence of cloud. Atmospheric Molecular Variables ############################### Elastic\_Mol\_Extinction :Type: *double* :Dimensions: *scan\_angles, points* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: *double Elastic\_Mol\_Extinction(scan\_angles, points)* This variable provides the value of molecular extinction coefficient at elastic wavelength in m\ :sup:`-1` at a given scan angle and altitude (points). The values are calculated from standard models or from radiosounding (submitted to the SCC as external input files) LR\_Mol :Type: *double* :Dimensions: N/A :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double LR_Mol`` The value of calculated molecular lidar ratio in sr. Emission\_Wave\_Mol\_Trasmissivity :Type: *double* :Dimensions: *scan\_angles, points* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double Emission_Wave_Mol_Trasmissivity(scan_angles, points)`` This variable provides the value of molecular trasmissitivy at emission wavelength at a given scan angle and altitude (*points*). Detection\_Wave\_Mol\_Trasmissivity :Type: *double* :Dimensions: *scan\_angles, points* :Location: Included in all the Low Resolution SCC L1 Product files :Definition: ``double Detection_Wave_Mol_Trasmissivity(scan_angles, points)`` This variable provides the value of molecular trasmissitivy at detection wavelength at a given scan angle and altitude (*points*). Aerosol Related Variables ######################### elT :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves one single elastic channel not split in near and far range :Definition: ``double elT(time, points)`` This variable contains the time-series of the RCS corresponding to an elastic channel. The RCS may correspond to a single physical lidar channel or to two physical channels (one optimized for the near range and the other for the far range) that have been glued by ELPP module. elT\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves one single elastic channel not split in near and far range :Definition: ``double elT_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elT*. elTnr :Variable name: *elTnr* :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves a near range elastic channel :Definition: ``double elTnr(time, points)`` This variable contains the time-series of the RCS corresponding to a near range elastic channel. If this variable is present also the corresponding *elTfr* variable should be present in the file. elTnr\_err :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves a near range elastic channel :Definition: ``double elTnr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elTnr*. elTfr :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves a far range elastic channel :Definition: ``double elTfr(time, points)`` This variable contains the time-series of the RCS corresponding to a far range elastic channel. If this variable is present also the corresponding *elTnr* variable should be present in the file. elTfr\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves a far range elastic channel :Definition: ``double elTfr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elTfr*. vrRN2 :Type: * double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves one vibro-rotational N2 Raman channel not split in near and far range :Definition: ``double vrRN2(time, points)`` This variable contains the time-series of the RCS corresponding to a vibro-rotational N2 Raman channel. The RCS may correspond to a single physical lidar channel or to two physical channels (one optimized for the near range and the other for the far range) that have been glued by ELPP module. vrRN2\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves one vibro-rotational N2 Raman channel not split in near and far range :Definition: ``double vrRN2_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *vrRN2*. vrRN2nr :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves a near range vibro-rotational N2 Raman channel :Definition: ``double vrRN2nr(time, points)`` This variable contains the time-series of the RCS corresponding to a near range vibro-rotationl N2 Raman. If this variable is present also the corresponding *vrRN2fr* variable should be present in the file. vrRN2nr\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves a near range vibro-rotational N2 Raman channel :Definition: ``double vrRN2nr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *vrRN2nr*. vrRN2fr :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves a far range vibro-rotational N2 Raman channel :Definition: ``double vrRN2fr(time, points)`` This variable contains the time-series of the RCS corresponding to a far range vibro-rotationl N2 Raman. If this variable is present also the corresponding *vrRN2nr* variable should be present in the file. vrRN2fr\_err :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves a far range vibro-rotational N2 Raman channel :Definition: ``double vrRN2fr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *vrRN2fr*. Polarization related variables ############################## elPT :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels not split in near and far range :Definition: ``double elPT(time, points)`` This variable contains the time-series of the RCS corresponding to the elastic polarization component which is transmitted by the polarization sensitive optical subsystem. This component may correspond to a total, cross or parallel polarization component depending on the particular system configuration. Moreover the RCS may correspond to a single physical lidar channel or to two physical channels (one optimized for the near range and the other for the far range) that have been glued by ELPP module. elPT\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves spolarization sensitive elastic channels not split in near and far range :Definition: ``double elPT_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elPT*. elPTnr :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double elPTnr(time, points)`` This variable contains the time-series of the RCS corresponding to the near range elastic polarization component which is transmitted by the polarization sensitive optical subsystem. This component may correspond to a total, cross or parallel polarization component depending on the particular system configuration. If this variable is present also the corresponding *elPTfr* variable should be present in the file. elPTnr\_err :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double elPTnr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elPTnr*. elPTfr :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double elTfr(time, points)`` This variable contains the time-series of the RCS corresponding to the far range elastic polarization component which is transmitted by the polarization sensitive optical subsystem. This component may correspond to a total, cross or parallel polarization component depending on the particular system configuration. If this variable is present also the corresponding elPTnr variable should be present in the file. elPTfr\_err :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double elPTfr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elPTfr*. elPR :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels not split in near and far range :Definition: ``double elPR(time, points)`` This variable contains the time-series of the RCS corresponding to the elastic polarization component which is reflected by the polarization sensitive optical subsystem. This component may correspond to a total, cross or parallel polarization component depending on the particular system configuration. Moreover the RCS may correspond to a single physical lidar channel or to two physical channels (one optimized for the near range and the other for the far range) that have been glued by ELPP module. elPR\_err :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels not split in near and far range :Definition: ``double elPR_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elPR*. elPRnr :Type: *double* :Dimensions: * time, points* :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double elPTnr(time, points)`` This variable contains the time-series of the RCS corresponding to the near range elastic polarization component which is reflected by the polarization sensitive optical subsystem. This component may correspond to a total, cross or parallel polarization component depending on the particular system configuration. If this variable is present also the corresponding *elPRfr* variable should be present in the file. elPRnr\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: `` double elPRnr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elPRnr*. elPRfr :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double elPRfr(time, points)`` This variable contains the time-series of the RCS corresponding to the far range elastic polarization component which is reflected by the polarization sensitive optical subsystem. This component may correspond to a total, cross or parallel polarization component depending on the particular system configuration. If this variable is present also the corresponding *elPRnr* variable should be present in the file. elPRfr\_err :Type: *double* :Dimensions: *time, points* :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double elPRfr_err(time, points)`` This variable describes the statistical uncertainties corresponding to the variable *elPRfr*. G\_T :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double G_T`` G polarization cross-talk factor value corresponding to the polarization transmitted channel. G\_T\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double G_T_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *G\_T*. G\_T\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double G_T_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *G\_T*. H\_T :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double H_T`` H polarization cross-talk factor value corresponding to the polarization transmitted channel. H\_T\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double H_T_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *H\_T*. H\_T\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double H_T_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *H\_T*. G\_R :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double G_R`` G polarization cross-talk factor value corresponding to the polarization reflected channel. G\_R\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double G_R_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *G\_R*. G\_R\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: `` double G_R_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *G\_R*. H\_R :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double H_R`` H polarization cross-talk factor value corresponding to the polarization reflected channel. H\_R\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double H_R_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *H\_R*. H\_R\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double H_R_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *H\_R*. Polarization\_Channel\_Gain\_Factor :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor`` This variable reports the value of the gain ratio of the reflected and transmitted polarization channels. Polarization\_Channel\_Gain\_Factor\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor*. Polarization\_Channel\_Gain\_Factor\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor*. Polarization\_Channel\_Gain\_Factor\_Correction :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction`` This variable reports the value of the correction to the gain ratio of the reflected and transmitted polarization channels. Polarization\_Channel\_Gain\_Factor\_Correction\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable Polarization\_Channel\_Gain\_Factor\_Correction Polarization\_Channel\_Gain\_Factor\_Correction\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor\_Correction*. G\_T\_Near\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double G_T_Near_Range`` G polarization cross-talk factor value corresponding to the near range polarization transmitted channel. G\_T\_Near\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double G_T_Near_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *G\_T\_Near\_Range*. G\_T\_Near\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double G_T_Near_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *G\_T\_Near\_Range*. H\_T\_Near\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double H_T_Near_Range`` H polarization cross-talk factor value corresponding to the near range polarization transmitted channel. H\_T\_Near\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double H_T_Near_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *H\_T\_Near\_Range*. H\_T\_Near\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double H_T_Near_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *H\_T\_Near\_Range*. G\_R\_Near\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double G_R_Near_Range`` G polarization cross-talk factor value corresponding to the near range polarization reflected channel. G\_R\_Near\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double G_R_Near_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *G\_R\_Near\_Range*. G\_R\_Near\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double G_R_Near_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *G\_R\_Near\_Range*. H\_R\_Near\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double H_R_Near_Range`` H polarization cross-talk factor value corresponding to the near range polarization reflected channel. H\_R\_Near\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double H_R_Near_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *H\_R\_Near\_Range*. H\_R\_Near\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double H_R_Near_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *H\_R\_Near\_Range*. Polarization\_Channel\_Gain\_Factor\_Near\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Near_Range`` This variable reports the value of the gain ratio of the near range reflected and transmitted polarization channels. Polarization\_Channel\_Gain\_Factor\_Near\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Near_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Near\_Range\_Factor*. Polarization\_Channel\_Gain\_Factor\_Near\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Near_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor\_Near\_Range*. Polarization\_Channel\_Gain\_Factor\_Correction\_Near\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Near_Range`` This variable reports the value of the correction to the near range gain ratio of the reflected and transmitted polarization channels. Polarization\_Channel\_Gain\_Factor\_Correction\_Near\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Near_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable Polarization\_Channel\_Gain\_Factor\_Correction\_Near\_Range Polarization\_Channel\_Gain\_Factor\_Correction\_Near\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves near range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Near_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor\_Correction\_Near\_Range*. G\_T\_Far\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double G_T_Far_Range`` G polarization cross-talk factor value corresponding to the far range polarization transmitted channel. G\_T\_Far\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double G_T_Far_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *G\_T\_Far\_Range*. G\_T\_Far\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double G_T_Far_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *G\_T\_Far\_Range*. H\_T\_Far\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double H_T_Far_Range`` H polarization cross-talk factor value corresponding to the far range polarization transmitted channel. H\_T\_Far\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double H_T_Far_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *H\_T\_Far\_Range*. H\_T\_Far\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double H_T_Far_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *H\_T\_Far\_Range*. G\_R\_Far\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double G_R_Far_Range`` G polarization cross-talk factor value corresponding to the far range polarization reflected channel. G\_R\_Far\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double G_R_Far_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *G\_R\_Far\_Range*. G\_R\_Far\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double G_R_Far_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *G\_R\_Far\_Range*. H\_R\_Far\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double H_R_Far_Range`` H polarization cross-talk factor value corresponding to the far range polarization reflected channel. H\_R\_Far\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double H_R_Far_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *H\_R\_Far\_Range*. H\_R\_Far\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double H_R_Far_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *H\_R\_Far\_Range*. Polarization\_Channel\_Gain\_Factor\_Far\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Far_Range`` This variable reports the value of the gain ratio of the far range reflected and transmitted polarization channels. Polarization\_Channel\_Gain\_Factor\_Far\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Far_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Far\_Range\_Factor*. Polarization\_Channel\_Gain\_Factor\_Far\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Far_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor\_Far\_Range*. Polarization\_Channel\_Gain\_Factor\_Correction\_Far\_Range :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Far_Range`` This variable reports the value of the correction to the far range gain ratio of the reflected and transmitted polarization channels. Polarization\_Channel\_Gain\_Factor\_Correction\_Far\_Range\_Statistical\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Far_Range_Statistical_Err`` This variable describes the statistical uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor\_Correction\_Far\_Range*. Polarization\_Channel\_Gain\_Factor\_Correction\_Far\_Range\_Systematic\_Err :Type: *double* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves far range polarization sensitive elastic channels :Definition: ``double Polarization_Channel_Gain_Factor_Correction_Far_Range_Systematic_Err`` This variable describes the systematic uncertainties corresponding to the variable *Polarization\_Channel\_Gain\_Factor\_Correction\_Far\_Range*. Depolarization\_Calibration\_Type :Type: *integer* :Dimensions: N/A :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``int Depolarization_Calibration_Type`` This variable describes the type of depolarization calibration that has been performed. A value of 1 means automatic calibration made the the SCC, a value of 2 means manual calibration inserted into the SCC database. Molecular\_Linear\_Depolarization\_Ratio :Type: *double* :Dimensions: *scan\_angles,points* :Location: Present if the Low Resolution SCC L1 Product involves polarization sensitive elastic channels :Definition: ``double Molecular_Linear_Depolarization_Ratio(scan_angles, points)`` This variable report the value of molecular linear depolarization ration for at given scan angles and at given altitude (*points*). This profile is calculated on the base of the atmospheric data from standard models or radiosonding submitted by the user as separate file. The altitude scale at which each RCS within the time-series reported by the variables *elT, elTnr, elTfr, vrRN2, vrRN2nr, vrRN2fr, elPT, elPTnr, elPTfr, elPR, elPRnr, elPRfr*, refer to can be obtained as:: H(laser_pointing_angle_of_profiles(time),points) The total signal (:math:`I_{total}`) and the volume depolarization ratio (:math:`\delta`) can be calculated out of reflected (:math:`I_{R}`) and transmitted (:math:`I_{T}`) polarization component intensities using the following equations: .. math:: \delta^{*} = \frac{K}{\eta^{*}}\frac{I_R}{I_T} .. math:: \delta = \frac{\delta^{*} (G_T + H_T) - (G_R + H_R)}{(G_R - H_R) - \delta_{*}(G_T - H_T)} .. math:: I_{total} \propto \frac{\eta^{*}}{K} H_R I_T - H_T I_R where :math:`\eta^{*}` is the gain ratio of the reflected and transmitted polarization channels (variable *Polarization\_Channel\_Gain\_Factor*); :math:`K` is the correction to the gain ratio of the reflected and transmitted polarization channels (variable *Polarization\_Channel\_Gain\_Factor\_Correction*); :math:`I_{R}` is the intensity of the reflected polarization component (variable *elPR*); :math:`I_{T}` is the intensity of the transmitted polarization component (variable *elPT*); and :math:`G_{T}`, :math:`H_{T}`, :math:`G_{R}`, and :math:`H_{R}` are the polarization cross-talk parameters (variables *G\_T*, *H\_T*, *G\_R*, and *H\_R*). Low Resolution SCC L1 Product Format: global attributes ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In this section all the possible Low Resolution SCC L1 Product global attributes are reported. There are some global attributes that are mandatory and have to be present in all the Low Resolution SCC L1 Product files while there are others that have to be present only in specific cases. Location :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The name of site where the measurements have been performed System :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The name of the lidar system used to perform the measurements Latitude\_degrees\_north :Type: *double* :Location: Included in all the Low Resolution SCC L1 Product files The latitude (in degrees North) of the measurement site Longitude\_degrees\_east :Type: *double* :Location: Included in all the Low Resolution SCC L1 Product files The longitude (in degrees East) of the measurement site Altitude\_meter\_asl :Type: *double* :Location: Included in all the Low Resolution SCC L1 Product files The altitude (in m above see level) of the measurement site Measurement\_ID :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files Within the SCC all the measurement sessions is identified by a string called *Measurement\_ID* uniquely. This gobal attributes provides this string. Measurement\_Start\_Date :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The start date of the measurements. The format in which this date is written is specified in the gobal attribute *Measurement\_Date\_Format*. Measurement\_Date\_Format :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The format in which the global attribute *Measurement\_Start\_Date* is given. Measurement\_Start\_Time\_UT :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The start time (UT) of the measurements. The format in which this time is written is specified in the global attribute *Measurement\_Time\_Format*. Measurement\_Time\_Format :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The format in which the global attribute *Measurement\_Start\_Time\_U*\ T is given. Comments :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files This string can contain comments of the measurement session Overlap\_File\_Name :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files for which an overlap file has been submitted by the data originator. The name of the overlap file to use for overlap correction. LR\_File\_Name :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files corresponding to elastic only retrieval and for which an lidar ratio profile file has been submitted by the data originator. The name of the lidar ratio file containing the profile of particle lidar ratio values to use as input in the elastic only retrieval. SCCPreprocessingVersion :Type: *string* :Location: Included in all the Low Resolution SCC L1 Product files The version of SCC used to produce the current Low Resolution SCC L1 Product Low Resolution SCC L1 Product Filename -------------------------------------- The filename of the Low Resolution SCC L1 Products has the following format:: measurementid_prodid.nc The *measurementid* is a 12 characters alphanumeric string identifying the measurement session at which the product refers to. The *measurementid* (which is unique for a given measurement session) allows to fully trance the SCC analysis performed on the current product. This can be done because each measurement session is recorded in a SCC database using the same string. In the same database the measurement session is linked to the lidar configuration used to analyze the data (which is recorded and fully characterized in the SCC database providing all the channel details) and to a set of optical products to calculate. The *prodid* is a numeric string identifying the optical product that has to be calculated by SCC (in particular ELDA module) by applying the optical retrieval algorithm on the current pre-processed L1 product. Different product types are defined within the SCC. The contents of a Low Resolution SCC L1 product depends on the type of the product specified in the its filename by prodid string. In particular only the **Aerosol Related Variables **\ and\ ** Polarization related variables** specified in the section 2.2 can change depending on product type. In Tab. 3.1 are reported the product-type related variables for each optical product type. To link the *prodid* string with the corresponding product type the SCC database a proper query to the SCC database should be addressed. **Table 3.1:** Possible variables that can be found in the SCC L1 Products for each optical product type +--------------------------------------------------------------+---------------------------------------------------+ | Product type | Possible variables in Low Resolution L1 Product | +--------------------------------------------------------------+---------------------------------------------------+ | Extinction only | vrRN2, vrRN2nr, vrRN2fr | | | | | | vrRN2\_err, vrRN2nr\_err, vrRN2fr\_err | +--------------------------------------------------------------+---------------------------------------------------+ | Elastic Backscatter | elT, elTnr, elTfr | | | | | Elastic Backscatter + Particle Linear Depolarization Ratio | elT\_err, elTnr\_err, elTfr\_err | | | | | | elPR, elPRnr, elPRfr | | | | | | elPR\_err, elPRnr\_err, elPRfr\_err | | | | | | elPT, elPTnr, elPTfr | | | | | | elPT\_err, elPTnr\_err, elPTfr\_err | +--------------------------------------------------------------+---------------------------------------------------+ | Raman Backscatter | elT, elTnr, elTfr | | | | | Raman Backscatter + Particle Linear Depolarization Ratio | elT\_err, elTnr\_err, elTfr\_err | | | | | Lidar Ratio | elPR, elPRnr, elPRfr | | | | | | elPR\_err, elPRnr\_err, elPRfr\_err | | | | | | elPT, elPTnr, elPTfr | | | | | | elPT\_err, elPTnr\_err, elPTfr\_err | | | | | | vrRN2, vrRN2nr, vrRN2fr | | | | | | vrRN2\_err, vrRN2nr\_err, vrRN2fr\_err | +--------------------------------------------------------------+---------------------------------------------------+
