diff -r ae93ea881019 -r f697817dad5f docs/depolarization/depolarization.rst --- a/docs/depolarization/depolarization.rst Sun Oct 23 23:12:51 2016 +0300 +++ b/docs/depolarization/depolarization.rst Mon Oct 24 16:38:14 2016 +0300 @@ -1,316 +1,164 @@ -**Single Calculus Chain ** - -**version: 4.0** - -**date: Date (fixed)** - -**DRAFT** - -This document describes the main changes implemented in the SCC v4.0 -with respect to what already provided in the SCC v3.11. It will be also -reported the modifications the users need to perform to run the new -version of SCC. - -Table of Contents - -1. Particle Linear Depolarization Ratio Implementation 3 - -1.1 Background 3 - -1.2 Polarization calibration 4 +1. Particle Linear Depolarization Ratio Implementation +====================================================== -1.3 SCC procedure to calculate the PLDRP 4 - -2.Changes of the SCC input format 8 - -3.Real Example 10 - -3.1 Modification of polarization channel parameters 10 - -3.2 Definition of new calibration configuration and product 12 +The most important improvement included in the SCC v4.0 is the implementation of a new optical product which is the particle linear depolarization ratio. -3.3 Definition of “Raman/Elastic backscatter and linear depolarization -ratio” 16 - -Particle Linear Depolarization Ratio Implementation -=================================================== - -The most important improvement included in the SCC v4.0 is the -implementation of a new optical product which is the particle linear -depolarization ratio. - -**Background** +1.1 Background -------------- -The calculation of the volume linear depolarization ratio profile -(*VLDR*) and particle linear depolarization ratio profile (*PLDR*) needs -two different steps: - -1. the calibration of the polarization sensitive lidar channels; - -2. the calculation of the *VLDR* or *PLDR* itself. +The calculation of the volume linear depolarization ratio profile (*VLDR*) and particle linear depolarization ratio profile (*PLDR*) needs two different steps: -The SCC allows the user to make both the above points. In particular the -calibration step is made by a completely new module called -**scc\_calibrator** which computes the *apparent calibration factor* -h\ :sup:`\*` out of the pre-processed data provided by the standard -**ELPP** (Earlinet Lidar Pre-Processor) module and it records it in the -SCC database (SCC\_DB). Once logged into the SCC\_DB this factor can be -used whenever it is necessary. +#. the calibration of the polarization sensitive lidar channels; +#. the calculation of the *VLDR* or *PLDR* itself. + +The SCC allows the user to make both the above points. In particular the calibration step is made by a completely new module called **scc\_calibrator** which computes the *apparent calibration factor* :math:`\beta^*` out of the pre-processed data provided by the standard **ELPP** (Earlinet Lidar Pre-Processor) module and it records it in the SCC database (SCC\_DB). Once logged into the SCC\_DB this factor can be used whenever it is necessary. + +The raw lidar calibration measurements should be put in a NetCDF file which has the same structure as the “standard” raw SCC NetCDF input file (for more details see sections 2 and 3.2). -The raw lidar calibration measurements should be put in a NetCDF file -which has the same structure as the “standard” raw SCC NetCDF input file -(for more details see sections 2 and 3.2). +New signal types have been introduced to take into account special channel configurations used for calibration purposes. -New signal types have been introduced to take into account special -channel configurations used for calibration purposes. +Moreover new product types for both calibration and *PLDR* calculation have been defined. As, in principle, it is possible to calculate the *PLDR* only when the aerosol backscatter coefficient profile is available the following new products have been defined: -Moreover new product types for both calibration and *PLDR* calculation -have been defined. As, in principle, it is possible to calculate the -*PLDR* only when the aerosol backscatter coefficient profile is -available the following new products have been defined: - -1. *Linear polarization calibration (factor* h) *(product\_type\_id=6);* - -2. *Raman backscatter and linear depolarization ratio +#. *Linear polarization calibration (factor* h) *(product\_type\_id=6);* +#. *Raman backscatter and linear depolarization ratio (product\_type\_id=7);* - -3. *Elastic backscatter and linear depolarization ratio +#. *Elastic backscatter and linear depolarization ratio (product\_type\_id=8).* -The first product in the above list is used only for calibration while -the other two are used for the calculation of *PLDR*. Basically, in most -of the cases, the products 2 and 3 are equivalent to the corresponding -backscatter product types with the exception that also the following new -variables are available: +The first product in the above list is used only for calibration while the other two are used for the calculation of *PLDR*. Basically, in most of the cases, the products 2 and 3 are equivalent to the corresponding backscatter product types with the exception that also the following new variables are available: -double VolumeDepol(Length) ; - -double ErrorVolumeDepol(Length) ; +.. code-block:: python -ErrorVolumeDepol:long\_name = "absolute error of VolumeDepol" ; - -double ParticleDepol(Length) ; + double VolumeDepol(Length) ; + double ErrorVolumeDepol(Length) ; + ErrorVolumeDepol:long\_name = "absolute error of VolumeDepol" ; + double ParticleDepol(Length) ; + double ErrorParticleDepol(Length) ; + ErrorParticleDepol:long\_name = "absolute error of ParticleDepol" ; -double ErrorParticleDepol(Length) ; - -ErrorParticleDepol:long\_name = "absolute error of ParticleDepol" ; - -**Polarization calibration** +1.2 Polarization calibration ---------------------------- -An important point is the definition of reliable *PLDR* calibration -procedures. Within EARLINET the following calibration procedures are -currently used: +An important point is the definition of reliable *PLDR* calibration procedures. Within EARLINET the following calibration procedures are currently used: -a) Rayleigh calibration; - -b) +45 calibration method, or D90 calibration method (made by +45 and - -45 measurements); - -c) 3 signals (total, cross and parallel). + a) Rayleigh calibration; + b) +45 calibration method, or D90 calibration method (made by +45 and -45 measurements); + c) 3 signals (total, cross and parallel). -It is well known that method a) could produce easily large errors on -*PLDR* which cannot be controlled. For this reason only the methods b) -and c) can be used to provide reliable polarization calibrations and so -only those methods will be implemented in the SCC. - -For what it concerns the method c) it, basically, requires to solve the -equation: +It is well known that method a) could produce easily large errors on *PLDR* which cannot be controlled. For this reason only the methods b) and c) can be used to provide reliable polarization calibrations and so only those methods will be implemented in the SCC. -in two different of atmospheric layers with considerably different -*VLDR*. So to calibrate in this way the implementation of automatic -layer identification in the SCC is required. As at moment this feature -is not yet available within the SCC *ONLY* the method b) is considered. +For what it concerns the method c) it, basically, requires to solve the equation: -SCC procedure to calculate the PLDRP ------------------------------------- - -According to what mentioned before the SCC calculates the *PLDR* through -the following steps: +.. math:: + \alpha_s P_s + \alpha_p P_p = P -1. The user needs to create a new system configuration in the SCC\_DB - including only lidar channels used for the calibration. One (or more) - *Linear polarization calibration (product\_type\_id=6)* product - should be associated to this new configuration (see section 3.2 for - more details); +in two different of atmospheric layers with considerably different *VLDR*. So to calibrate in this way the implementation of automatic layer identification in the SCC is required. As at moment this feature is not yet available within the SCC *ONLY* the method b) is considered. + +1.3 SCC procedure to calculate the PLDRP +---------------------------------------- + +According to what mentioned before the SCC calculates the *PLDR* through the following steps: -2. This new system configuration should contain only the polarization - channels in the configuration used for the calibration (for example - rotated in the polarization plane of +45 degrees). A channel in - calibration measurement configuration should have a *DIFFERENT* - channel ID from the channel ID corresponding to the same channel in - standard measurement configuration. For example, if a system has two - polarization channels which in standard measurement configuration - correspond to the channel ID=1 and 2 respectively, the same physical - channels under calibration measurement configuration should - correspond to different channel IDs (let's say ID=3 and 4 for the +45 - degrees polarization rotated channels and ID=5 and 6 for the -45 - degrees polarization rotated ones in case D90 calibration method is - used). Moreover, the polarization channels should be labeled - correctly using the new signal types available (*+45elPT, +45elPR, - -45elPT, -45elPR, +45elPTnr, +45elPTfr, +45elPRnr, +45elPRfr, - -45elPTnr, -45elPTfr, -45elPRnr, -45elPRfr).* For more details see - section 3.2; +#. The user needs to create a new system configuration in the SCC\_DB including only lidar channels used for the calibration. One (or more) *Linear polarization calibration (product\_type\_id=6)* product should be associated to this new configuration (see section 3.2 for more details); + +#. This new system configuration should contain only the polarization channels in the configuration used for the calibration (for example rotated in the polarization plane of +45 degrees). A channel in calibration measurement configuration should have a *DIFFERENT* channel ID from the channel ID corresponding to the same channel in standard measurement configuration. For example, if a system has two polarization channels which in standard measurement configuration correspond to the channel ID=1 and 2 respectively, the same physical channels under calibration measurement configuration should correspond to different channel IDs (let's say ID=3 and 4 for the +45 degrees polarization rotated channels and ID=5 and 6 for the -45 degrees polarization rotated ones in case D90 calibration method is used). Moreover, the polarization channels should be labeled correctly using the new signal types available (*+45elPT, +45elPR, -45elPT, -45elPR, +45elPTnr, +45elPTfr, +45elPRnr, +45elPRfr, -45elPTnr, -45elPTfr, -45elPRnr, -45elPRfr).* For more details see section 3.2; -3. In SCC v4.0 the polarization channels are *NOT* labeled on the base - of their polarization state (as it was done in the SCC v3.11) but - *ALWAYS* as transmitted and reflected channels. So the channels that - in SCC v3.11 were labeled as *elCP, elCPnr, elCPfr, elPP, elPPnr - elPPfr* will be labeled in SCC v4.0 as *elPR, elPRnr elPRfr elPT, - elPTnr elPTfr* where the letter *T* stands from transmitted and the - letter *R* for reflected. +#. In SCC v4.0 the polarization channels are *NOT* labeled on the base of their polarization state (as it was done in the SCC v3.11) but *ALWAYS* as transmitted and reflected channels. So the channels that in SCC v3.11 were labeled as *elCP, elCPnr, elCPfr, elPP, elPPnr elPPfr* will be labeled in SCC v4.0 as *elPR, elPRnr elPRfr elPT, elPTnr elPTfr* where the letter *T* stands from transmitted and the letter *R* for reflected. -**WARNING:** In switching from the SCC v3.11 to SCC v4.0 the following -modifications have been made on *ALL* channels of *ALL* registered -configurations: - -*elPP→elPR* - -*elCP→elPT* +:WARNING: In switching from the SCC v3.11 to SCC v4.0 the following modifications have been made on *ALL* channels of *ALL* registered configurations: + *elPP→elPR* -*elPPnr→elPRnr* - -*elPPfr→ elPRfr* - -*elCPnr→ elPTnr* + *elCP→elPT* -*elCPfr→ elPTfr* + *elPPnr→elPRnr* -Please be sure these modifications reflect to your actual lidar setup -(cross channels are transmitted and parallel channels are reflected); - -1. The user needs to submit a file (same format as raw SCC input file) - containing the raw data for the lidar channels defined at the point 1 - (see section 3.2 for more details); + *elPPfr→ elPRfr* -2. The file at point 2 is pre-processed by **ELPP** module which applies - the standard pre-processing procedures applied to “standard” lidar - data; - -3. The pre-processed files are then processed by the new modules - **scc\_calibrator** which calculates h\ :sup:`\*` *the apparent - calibration factor* and logs it into the SCC\_DB; + *elCPnr→ elPTnr* -4. The user needs to create a new system configuration in the SCC\_DB - (which should be different from the one used for the calibration) and - associate it the new product *Raman backscatter and linear - depolarization ratio (product\_type\_id=7)* or *Elastic backscatter - and linear depolarization ratio (product\_type\_id=8).* Alternatively - the calculation of those products can be added to an already existing - lidar configuration as long as it is different from the calibration - one; + *elCPfr→ elPTfr* + + Please be sure these modifications reflect to your actual lidar setup(cross channels are transmitted and parallel channels are reflected); -5. The product defined at point 5 should be linked to the product - containing the polarization calibration (defined at point 1) in a way - that the *apparent calibration factor* can be selected from the - SCC\_DB (see section 3.3 and in particular figure 3.4); - -6. The user needs to submit another SCC raw data file containing the - “standard” measurements; - -7. Finally **ELPP** and **ELDA** will produce a b-file containing - backscatter coefficient profile and *PLDR*. In particular this - calculation is made in two different steps: from the pre-processed - lidar polarization signals, and taking into account the *apparent - calibration factor* and the *calibration factor correction K* - (defined as option of *Linear polarization calibration* product\ *)* - written into the SCC\_DB, an “apparent” *VLDR* *d\ :sup:`\*`* is - calculated. Even if *d\ :sup:`\*`* is a calibrated quantity it can be - still affected by possible systematic errors due to not perfect - optics or alignment of the system; +4. The user needs to submit a file (same format as raw SCC input file) containing the raw data for the lidar channels defined at the point 1 (see section 3.2 for more details); +#. The file at point 2 is pre-processed by **ELPP** module which applies the standard pre-processing procedures applied to “standard” lidar data; +#. The pre-processed files are then processed by the new modules **scc\_calibrator** which calculates :math:`\eta^*` *the apparent calibration factor* and logs it into the SCC\_DB; +#. The user needs to create a new system configuration in the SCC\_DB (which should be different from the one used for the calibration) and associate it the new product *Raman backscatter and linear depolarization ratio product\_type\_id=7)* or *Elastic backscatter and linear depolarization ratio (product\_type\_id=8).* Alternatively the calculation of those products can be added to an already existing lidar configuration as long as it is different from the calibration one; +#. The product defined at point 5 should be linked to the product containing the polarization calibration (defined at point 1) in a way that the *apparent calibration factor* can be selected from the SCC\_DB (see section 3.3 and in particular figure 3.4); +#. The user needs to submit another SCC raw data file containing the “standard” measurements; +#. Finally **ELPP** and **ELDA** will produce a b-file containing backscatter coefficient profile and *PLDR*. In particular this calculation is made in two different steps: from the pre-processed lidar polarization signals, and taking into account the *apparent calibration factor* and the *calibration factor correction K* (defined as option of *Linear polarization calibration* product\ *)* written into the SCC\_DB, an “apparent” *VLDR* :math:`\delta^*` is calculated. Even if :math:`\delta^*` is a calibrated quantity it can be still affected by possible systematic errors due to not perfect optics or alignment of the system; -8. To take into account these errors a corrected *VLDR* (*d)* is - calculated using the *polarization cross-talk correction parameters* - *G* and *H* calculated on the base of Müller matrix formalism. These - cross-talk correction parameters (*G* and *H*) are stored in the - SCC\_DB for each lidar channels (see section 3.1 in particular figure - 3.2). Finally the *PLDR* is calculated using the backscatter - coefficient profile and the molecular LDRP calculated by ELPP - considering the center wavelength and bandwidth of the channels - interference filter. +#. To take into account these errors a corrected *VLDR* (:math:`\delta`) is calculated using the *polarization cross-talk correction parameters* *G* and *H* calculated on the base of Müller matrix formalism. These cross-talk correction parameters (*G* and *H*) are stored in the SCC\_DB for each lidar channels (see section 3.1 in particular figure 3.2). Finally the *PLDR* is calculated using the backscatter coefficient profile and the molecular LDRP calculated by ELPP considering the center wavelength and bandwidth of the channels interference filter. + +The *apparent calibration factor* :math:`\eta^*` is calculated by the **scc\_calibrator** module as the geometrical mean of the ratio of the +/-45 degrees reflected to the +/- 45 degrees transmitted signals within an altitude calibration range defined by the users in the raw data input files. -The *apparent calibration factor* h\ :sup:`\*` is calculated by the -**scc\_calibrator** module as the geometrical mean of the ratio of the -+/-45 degrees reflected to the +/- 45 degrees transmitted signals within -an altitude calibration range defined by the users in the raw data input -files. +In case of +45 calibration method :math:`\eta^*` is calculated by: -In case of +45 calibration method h\ :sup:`\*` is calculated by: - -(1.1) +.. math:: + \eta^* = \frac{I_R}{I_T}(+45) While in case of D90 calibration method: -(1.2) +.. math:: + \eta^* = \sqrt{\frac{I_R}{I_T}(+45) \frac{I_R}{I_T}(-45)} **ELDA** module calculates the “apparent” *VLDR*: -(1.3) +.. math:: + \delta^* = \frac{K}{\eta^*} \cdot \frac{I_R}{I_T} the *VLDR* -(1.4) +.. math:: + \delta = \frac{\delta^*(G_T + H_T)-(G_R + H_R)}{(G_R - H_R) - \delta^*(G_T - H_T)} and the *PLDR* -(1.5) +.. math:: + \delta_{\alpha} = \frac{(1 + \delta_m)\delta R - (1 + \delta)\delta_m}{(1 + \delta_m)R - (1 + \delta)} where: -- h\ :sup:`\*` is the *apparent calibration factor* calculated by - **scc\_calibrator** + - :math:`\eta^*` is the *apparent calibration factor* calculated by **scc\_calibrator** + + - *K* is the *calibration factor correction* defined as polarization product option -- *K* is the *calibration factor correction* defined as polarization - product option + - :math:`I_T` and :math:`I_R` are the transmitted and the reflected signals in the polarization detection set-up -- *I\ :sub:`T`* and I\ *:sub:`R`* are the transmitted and the reflected - signals in the polarization detection set-up + - :math:`G_{T,R}` and :math:`H_{T,R}` are *polarization cross-talk correction parameters* for the transmitted and reflected signals used to correct for systematic errors. Both these factors are defined in the SCC\_DB for each lidar channel. -- *G\ :sub:`T,R`* and *H\ :sub:`T,R`* are *polarization cross-talk - correction parameters* for the transmitted and reflected signals used - to correct for systematic errors. Both these factors are defined in - the SCC\_DB for each lidar channel. + - :math:`\delta_m` is the molecular linear depolarization ratio calculated by ELPP + + - *R* is the backscatter ratio -- *d\ :sub:`m`* is the molecular linear depolarization ratio calculated - by ELPP +Please note once again that the polarization channels are described in terms of transmitted and reflected signals. This means that according to different lidar instrumental configurations, the transmitted or the reflected channel can contain total, perpendicular or parallel polarized signals. -- *R* is the backscatter ratio +In order to retrieve the backscatter profile the total signal must be obtained combining the transmitted and reflected polarized signals. The following formula is used: -Please note once again that the polarization channels are described in -terms of transmitted and reflected signals. This means that according to -different lidar instrumental configurations, the transmitted or the -reflected channel can contain total, perpendicular or parallel polarized -signals. +.. math:: + I_{total} \propto \frac{\eta^*}{K}H_R I_T - H_T I_R -In order to retrieve the backscatter profile the total signal must be -obtained combining the transmitted and reflected polarized signals. The -following formula is used: +The formulas above are general and can be adapted to all possible polarization lidar configurations selecting the right polarization cross-talk correction parameters (see Table 1.1). -(1.6) +Let's suppose, for example, we have the perpendicular polarized lidar signal on the transmitted channel and the parallel polarized on reflected channel. For an ideal system (no diattenuation and cross-talk) we have: -The formulas above are general and can be adapted to all possible -polarization lidar configurations selecting the right polarization -cross-talk correction parameters (see Table 1.1). +.. math:: + G_T=1 , \qquad H_T=-1, \qquad G_R=1, \qquad H_R=1 + +If, on the other hands, we have the perpendicular polarized lidar signal on reflected channel and the total polarized on the transmitted for and ideal system we have: -Let's suppose, for example, we have the perpendicular polarized lidar -signal on the transmitted channel and the parallel polarized on -reflected channel. For an ideal system (no diattenuation and cross-talk) -we have: +.. math:: + G_T=1 , \qquad H_T=0, \qquad G_R=1, \qquad H_R=-1 -If, on the other hands, we have the perpendicular polarized lidar signal -on reflected channel and the total polarized on the transmitted for and -ideal system we have: -**Table 1.1:** Polarization cross-talk correction parameters for ideal -systems +**Table 1.1:** Polarization cross-talk correction parameters for ideal systems +----------------------+-----------------------------+-----------------+-----------------+-----------------+ | Laser polarization | Detected in lidar channel | -+----------------------+-----------------------------+-----------------+-----------------+-----------------+ ++ +-----------------------------+-----------------+-----------------+-----------------+ | | Transmitted | Reflected | -+----------------------+-----------------------------+-----------------+-----------------+-----------------+ -| | *G\ :sub:`T`* | *H\ :sub:`T`* | *G\ :sub:`R`* | *H\ :sub:`R`* | ++ +-----------------------------+-----------------+-----------------+-----------------+ +| | :math:`G_T` | :math:`H_T` | :math:`G_R` | :math:`H_R` | +----------------------+-----------------------------+-----------------+-----------------+-----------------+ | total | 1 | 0 | 1 | 0 | +----------------------+-----------------------------+-----------------+-----------------+-----------------+ @@ -319,163 +167,125 @@ | cross | 1 | -1 | 1 | -1 | +----------------------+-----------------------------+-----------------+-----------------+-----------------+ -The *apparent calibration factor* (h:sup:`\*`), *the calibration factor -correction* (*K*) and the *polarization cross-talk correction -parameters* are stored by **ELPP** module in the intermediate NetCDF -files using the following variables: +The *apparent calibration factor (:math:`\eta^*`), *the calibration factor correction* (*K*) and the *polarization cross-talk correction parameters* are stored by **ELPP** module in the intermediate NetCDF files using the following variables: -- *Polarization\_Channel\_Gain\_Factor (apparent calibration factor* – - h\ :sup:`\*`) - -- *Polarization\_Channel\_Gain\_Factor\_Correction (calib. factor - corr.* – *K*) - -- *G\_T* +testing the inline code :code:`test` -- *H\_T* - -- *G\_R* - -- *H\_R* + - :code:`Polarization_Channel_Gain_Factor` (*apparent calibration factor* - :math:`\eta^*` ) + - :code:`Polarization_Channel_Gain_Factor_Correction` (*calib. factor corr.* – *K*) + - :code:`G_T` + - :code:`H_T` + - :code:`G_R` + - :code:`H_R` -Finally new usecases have been defined to take into account all the -possible lidar configurations. The details on that are provided as a -separate file. +Finally new usecases have been defined to take into account all the possible lidar configurations. The details on that are provided as a separate file. -Changes of the SCC input format -=============================== +2. Changes of the SCC input format +================================== The following minor changes have been applied to raw SCC data format: -1. The optional variable *ID\_Range* has been *REMOVED*; +#. The optional variable *ID\_Range* has been *REMOVED*; +#. The *OPTIONAL* variable :code:`int Signal\_Type(channels)` has been added. The possible values are the same available in the SCC\_DB: -2. The *OPTIONAL* variable *int Signal\_Type(channels)* has been added. - The possible values are the same available in the SCC\_DB: - -0 *→* elT + :code:`0` :math:`\rightarrow` :code:`elT` -1 *→* elTnr - -2 *→* elTfr + :code:`1` :math:`\rightarrow` :code:`elTnr` -3 *→* vrRN2 + :code:`2` :math:`\rightarrow` :code:`elTfr` -4 *→* vrRN2nr + :code:`3` :math:`\rightarrow` :code:`vrRN2` -5 *→* vrRN2fr - -6 *→* elPR + :code:`4` :math:`\rightarrow` :code:`vrRN2nr` -7 *→* elPT + :code:`5` :math:`\rightarrow` :code:`vrRN2fr` -8 *→* pRRlow + :code:`6` :math:`\rightarrow` :code:`elPR` -9 *→* pRRhigh + :code:`7` :math:`\rightarrow` :code:`elPT` -10 *→* elPRnr + :code:`8` :math:`\rightarrow` :code:`pRRlow` -11 *→* elPRfr + :code:`9` :math:`\rightarrow` :code:`pRRhigh` -12 *→* elPTnr + :code:`10` :math:`\rightarrow` :code:`elPRnr` -13 *→* elPTfr - -14 *→* vrRH2O + :code:`11` :math:`\rightarrow` :code:`elPRfr` -15 *→* pRRhighnr + :code:`12` :math:`\rightarrow` :code:`elPTnr` -16 *→* pRRhighfr + :code:`13` :math:`\rightarrow` :code:`elPTfr` -17 *→* pRRlownr - -18 *→* pRRlowfr + :code:`14` :math:`\rightarrow` :code:`vrRH2O` -19 *→* vrRH2Onr + :code:`15` :math:`\rightarrow` :code:`pRRhighnr` -20 *→* vrRH2Ofr + :code:`16` :math:`\rightarrow` :code:`pRRhighfr` -21 *→* elTunr - -*22 → +45elPT* + :code:`17` :math:`\rightarrow` :code:`pRRlownr` -*23 → +45elPR* + :code:`18` :math:`\rightarrow` :code:`pRRlowfr` -*24 → -45elPT* + :code:`19` :math:`\rightarrow` :code:`vrRH2Onr` -*25 → -45elPR* + :code:`20` :math:`\rightarrow` :code:`vrRH2Ofr` -*26 → +45elPTnr* + :code:`21` :math:`\rightarrow` :code:`elTunr` -*27 → +45elPTfr* + :code:`22` :math:`\rightarrow` :code:`+45elPT` -*28 → +45elPRnr* - -*29 → +45elPRfr* + :code:`23` :math:`\rightarrow` :code:`+45elPR` -*30 → -45elPTnr* + :code:`24` :math:`\rightarrow` :code:`-45elPT` -*31 → -45elPTfr* + :code:`25` :math:`\rightarrow` :code:`-45elPR` -*32 → -45elPRnr* + :code:`26` :math:`\rightarrow` :code:`+45elPTnr` -*33 → -45elPRfr* + :code:`27` :math:`\rightarrow` :code:`+45elPTfr` -**WARNING:** It this variable is found in the SCC input file the -corresponding settings in the SCC database will be *overwritten*. Unless -you don't have any valid reason to overwrite the database value this -variable should not be used. + :code:`28` :math:`\rightarrow` :code:`+45elPRnr` + + :code:`29` :math:`\rightarrow` :code:`+45elPRfr` -1. The variables: + :code:`30` :math:`\rightarrow` :code:`-45elPTnr` -*double Pol\_Calib\_Range\_Min(channels)* + :code:`31` :math:`\rightarrow` :code:`-45elPTfr` -*double Pol\_Calib\_Range\_Max(channels) * + :code:`32` :math:`\rightarrow` :code:`-45elPRnr` -have been added. Both these variable are *mandatory* for any calibration -raw dataset. + :code:`33` :math:`\rightarrow` :code:`-45elPRfr` -These variable should be included only the polarization calibration -measurements and should specify the altitude range (meters) in which the -polarization calibration should be made. For more details see section -3.3; + :WARNING: It this variable is found in the SCC input file the corresponding settings in the SCC database will be *overwritten*. Unless you don't have any valid reason to overwrite the database value this variable should not be used. -1. The variable *Depolarization\_Factor* has been *removed*. +3. The variables: -The SCC v3.11 used this variable to get polarization calibration factor -for the calculation of the total signal out of cross and parallels ones. -As the SCC v4.0 is able to calculate the same parameter by itself, the -use of this variable is *NOT* possible anymore. The recommended way to -get a valid and quality assured depolarization calibration factor is to -submit to the SCC v4.0 a polarization calibration dataset and let the -SCC to calculate such factor. + .. code-block:: python + + double Pol\_Calib\_Range\_Min(channels) + double Pol\_Calib\_Range\_Max(channels) -To make this change more smooth and to provide the users with the -possibility to continue to analyze their data with the SCC v4.0 even if -a calibration dataset has not been submitted yet, it will be possible -for a *LIMITED* period of time to submit the calibration constant via -the SCC web interface. The SCC will keep track of the used calibration -method (automatic or manual). + have been added. Both these variable are *MANDATORY* for any calibration raw dataset. These variable should be included only the polarization calibration measurements and should specify the altitude range (meters) in which the polarization calibration should be made. For more details see section 3.3; + +4. The variable :code:`Depolarization_Factor` has been *REMOVED*. -**WARNING:** After this transition period *only* automatic calibration -will be allowed! + The SCC v3.11 used this variable to get polarization calibration factor for the calculation of the total signal out of cross and parallels ones. As the SCC v4.0 is able to calculate the same parameter by itself, the use of this variable is *NOT* possible anymore. The recommended way to get a valid and quality assured depolarization calibration factor is to submit to the SCC v4.0 a polarization calibration dataset and let the SCC to calculate such factor. + + To make this change more smooth and to provide the users with the possibility to continue to analyze their data with the SCC v4.0 even if a calibration dataset has not been submitted yet, it will be possible for a *LIMITED* period of time to submit the calibration constant via the SCC web interface. The SCC will keep track of the used calibration method (automatic or manual). -1. The new *optional* variable: + :WARNING: After this transition period *ONLY* automatic calibration will be allowed! -*string channel\_string\_ID(channels)* +5. The new *OPTIONAL* variable: -has been introduced. + :code:`string channel\_string\_ID(channels)` -Starting from SCC v4.0 the lidar channel can be identified not only by -using integers (as it happened until SCC v3.11) but also by using -strings. + has been introduced. + + Starting from SCC v4.0 the lidar channel can be identified not only by using integers (as it happened until SCC v3.11) but also by using strings. -The procedure implemented in the SCC v4.0 to recognize the lidar channel -within the raw lidar data is fully backward compatible (old format files -are accepted as they are by SCC v4.0). + The procedure implemented in the SCC v4.0 to recognize the lidar channel within the raw lidar data is fully backward compatible (old format files are accepted as they are by SCC v4.0). -**WARNING:** Please note that the definition of the new string variable -requires netCDF-4 format! The type *string* is not supported in netCDF-3 -format! + :WARNING: Please note that the definition of the new string variable requires netCDF-4 format! The type *string* is not supported in netCDF-3 format! Real Example ============