--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/_build/html/netcdf_file.html Thu Mar 15 10:46:04 2012 +0100 @@ -0,0 +1,1352 @@ + +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> + + +<html xmlns="http://www.w3.org/1999/xhtml"> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> + + <title>The SCC netCDF file format — Single Calculus Chain 0.2 documentation</title> + + <link rel="stylesheet" href="_static/nature.css" type="text/css" /> + <link rel="stylesheet" href="_static/pygments.css" type="text/css" /> + + <script type="text/javascript"> + var DOCUMENTATION_OPTIONS = { + URL_ROOT: '', + VERSION: '0.2', + COLLAPSE_INDEX: false, + FILE_SUFFIX: '.html', + HAS_SOURCE: true + }; + </script> + <script type="text/javascript" src="_static/jquery.js"></script> + <script type="text/javascript" src="_static/underscore.js"></script> + <script type="text/javascript" src="_static/doctools.js"></script> + <script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script> + <link rel="top" title="Single Calculus Chain 0.2 documentation" href="index.html" /> + <link rel="next" title="User management" href="user_managment.html" /> + <link rel="prev" title="Processing measurement" href="measurement_upload.html" /> + </head> + <body> + <div class="related"> + <h3>Navigation</h3> + <ul> + <li class="right" style="margin-right: 10px"> + <a href="genindex.html" title="General Index" + accesskey="I">index</a></li> + <li class="right" > + <a href="user_managment.html" title="User management" + accesskey="N">next</a> |</li> + <li class="right" > + <a href="measurement_upload.html" title="Processing measurement" + accesskey="P">previous</a> |</li> + <li><a href="index.html">Single Calculus Chain 0.2 documentation</a> »</li> + </ul> + </div> + + <div class="document"> + <div class="documentwrapper"> + <div class="bodywrapper"> + <div class="body"> + + <div class="section" id="the-scc-netcdf-file-format"> +<h1>The SCC netCDF file format<a class="headerlink" href="#the-scc-netcdf-file-format" title="Permalink to this headline">¶</a></h1> +<div class="section" id="rationale"> +<h2>Rationale<a class="headerlink" href="#rationale" title="Permalink to this headline">¶</a></h2> +<p>The Single Calculus Chain (SCC) is composed by two different modules:</p> +<ul class="simple"> +<li>pre-processing module ( scc_preprocessing)</li> +<li>optical processing module ( ELDA)</li> +</ul> +<p>To perfom aerosol optical retrievals the SCC needs not only the raw +lidar data but also a certain number of parameters to use in both +pre-processing and optical processing stages. The SCC gets these +parameters looking at two different locations:</p> +<ul class="simple"> +<li>Single Calculus Chain relational database (SCC_DB)</li> +<li>Input files</li> +</ul> +<p>There are some paramenters that can be found only in the input files +(those ones changing from measurement to measurement), others that can +be found only in the SCC_DB and other ones that can be found in both +these locations. In the last case, if a particular parameter is needed, +the SCC will search first in the input files and then in SCC_DB. If the +parameter is found in the input files the SCC will keep it without +looking into SCC_DB.</p> +<p>The input files have to be submitted to the SCC in NetCDF format. At the +present the SCC can handle four different types of input files:</p> +<ol class="arabic simple"> +<li>Raw Lidar Data</li> +<li>Sounding Data</li> +<li>Overlap</li> +<li>Lidar Ratio</li> +</ol> +<p>As already mentioned, the Raw Lidar Data file contains not only the +raw lidar data but also other parameters to use to perform the +pre-processing and optical processing. The Sounding Data file +contains the data coming from a correlative radiosounding and it is used +by the SCC for molecular density calculation. The Overlap file +contains the measured overlap function. The Lidar Ratio file contains +a lidar ratio profile to use in elastic backscatter retrievals. The +Raw Lidar Data file is of course mandatory and the Sounding Data, +Overlap and Lidar Ratio files are optional. If Sounding Data file +is not submitted by the user, the molecular density will be calculated +by the SCC using the “US Standard Atmosphere 1976”. If the Overlap +file is not submitted by the user, the SCC will get the full overlap +height from SCC_DB and it will produce optical results starting from +this height. If Lidar Ratio file is not submitted by the user, the +SCC will consider a fixed value for lidar ratio got from SCC_DB.</p> +<p>The user can decide to submit all these files or any number of them (of +course the file Raw Lidar Data is mandatory). For example the user +can submit together with the Raw Lidar Data file only the Sounding +Data file or only the Overlap file.</p> +<p>This document provides a detailed explanation about the structure of the +NetCDF input files to use for SCC data submission. All Earlinet groups +should read it carefully because they have to produce such kind of input +files if they want to use the SCC for their standard lidar retrievals. +Every comments or suggestions regarding this document can be sent to +Giuseppe D’Amico by e-mail at <tt class="docutils literal"><span class="pre">damico@imaa.cnr.it</span></tt></p> +<p>This document is available for downloading at <tt class="docutils literal"><span class="pre">www.earlinetasos.org</span></tt></p> +<p>In table tab:rawdata is reported a list of dimensions, variables and +global attributes that can be used in the NetCDF Raw Lidar Data input +file. For each of them it is indicated:</p> +<ul class="simple"> +<li>The name. For the multidimensional variables also the corresponding +dimensions are reported</li> +<li>A description explaining the meaning</li> +<li>The type</li> +<li>If it is mandatory or optional</li> +</ul> +<p>As already mentioned, the SCC can get some parameters looking first in +the Raw Lidar Data input file and then into SCC_DB. This means that +to use the parameters stored in SCC_DB the optional variables or +optional global attributes must not appear within Raw Lidar Data +file. This is the suggested and recommended way to use the SCC. Please +include optional parameters in the Raw Lidar Data only as an +exception.</p> +<p>In table tab:sounding, tab:overlap and tab:lr are reported all the +information about the structure of Sounding Data, Overlap and +Lidar Ratio input files respectively.</p> +</div> +<div class="section" id="example"> +<h2>Example<a class="headerlink" href="#example" title="Permalink to this headline">¶</a></h2> +<p>Let’s now consider an example of Raw Lidar Data input file. Suppose +we want to generate NetCDF input file corresponding to a measurement +with the following properties:</p> +<table border="1" class="docutils"> +<colgroup> +<col width="34%" /> +<col width="66%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td>Start Date</td> +<td><span class="math">\(30^{th}\)</span> January 2009</td> +</tr> +<tr class="row-even"><td>Start Time UT</td> +<td>00:00:01</td> +</tr> +<tr class="row-odd"><td>Stop Time UT</td> +<td>00:05:01</td> +</tr> +<tr class="row-even"><td>Station Name</td> +<td>Dummy station</td> +</tr> +<tr class="row-odd"><td>Earlinet call-sign</td> +<td>cc</td> +</tr> +<tr class="row-even"><td>Pointing angle</td> +<td>5 degrees with respect to the zenith</td> +</tr> +</tbody> +</table> +<p>Moreover suppose that this measurement is composed by the following +lidar channels:</p> +<ol class="arabic"> +<li><p class="first">1064 lidar channel</p> +<table border="1" class="docutils"> +<colgroup> +<col width="49%" /> +<col width="51%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td><p class="first last">Emission wavelength=1064nm</p> +</td> +<td><p class="first last">Detection wavelength=1064nm</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Time resolution=30s</p> +</td> +<td><p class="first last">Number of laser shots=1500</p> +</td> +</tr> +<tr class="row-odd"><td><p class="first last">Number of bins=3000</p> +</td> +<td><p class="first last">Detection mode=analog</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Range resolution=7.5m</p> +</td> +<td><p class="first last">Polarization state=total</p> +</td> +</tr> +</tbody> +</table> +</li> +<li><p class="first">532 cross lidar channel</p> +<table border="1" class="docutils"> +<colgroup> +<col width="47%" /> +<col width="53%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td><p class="first last">Emission wavelength=532nm</p> +</td> +<td><p class="first last">Detection wavelength=532nm</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Time resolution=60s</p> +</td> +<td><p class="first last">Number of laser shots=3000</p> +</td> +</tr> +<tr class="row-odd"><td><p class="first last">Number of bins=5000</p> +</td> +<td><p class="first last">Detection mode=photoncounting</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Range resolution=15m</p> +</td> +<td><p class="first last">Polarization state=cross</p> +</td> +</tr> +</tbody> +</table> +</li> +<li><p class="first">532 parallel lidar channel</p> +<table border="1" class="docutils"> +<colgroup> +<col width="47%" /> +<col width="53%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td><p class="first last">Emission wavelength=532nm</p> +</td> +<td><p class="first last">Detection wavelength=532nm</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Time resolution=60s</p> +</td> +<td><p class="first last">Number of laser shots=3000</p> +</td> +</tr> +<tr class="row-odd"><td><p class="first last">Number of bins=5000</p> +</td> +<td><p class="first last">Detection mode=photoncounting</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Range resolution=15m</p> +</td> +<td><p class="first last">Polarization state=parallel</p> +</td> +</tr> +</tbody> +</table> +</li> +<li><p class="first">607 <span class="math">\(N_2\)</span> vibrational Raman channel</p> +<table border="1" class="docutils"> +<colgroup> +<col width="47%" /> +<col width="53%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td><p class="first last">Emission wavelength=532nm</p> +</td> +<td><p class="first last">Detection wavelength=607nm</p> +</td> +</tr> +<tr class="row-even"><td><p class="first last">Time resolution=60s</p> +</td> +<td><p class="first last">Number of laser shots=3000</p> +</td> +</tr> +<tr class="row-odd"><td><p class="first last">Number of bins=5000</p> +</td> +<td><p class="first last">Detection mode=photoncounting</p> +</td> +</tr> +<tr class="row-even"><td colspan="2"><p class="first last">Range resolution=15m</p> +</td> +</tr> +</tbody> +</table> +</li> +</ol> +<p>Finally let’s assume we have also performed dark measurements before the +lidar measurements from the 23:50:01 UT up to 23:53:01 UT of +29:math:<cite>^mathrmth</cite> January 2009.</p> +<div class="section" id="dimensions"> +<h3>Dimensions<a class="headerlink" href="#dimensions" title="Permalink to this headline">¶</a></h3> +<p>Looking at table tab:rawdata we have to fix the following dimensions:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">points</span> +<span class="n">channels</span> +<span class="n">time</span> +<span class="n">nb_of_time_scales</span> +<span class="n">scan_angles</span> +<span class="n">time_bck</span> +</pre></div> +</div> +<p>The dimension <tt class="docutils literal"><span class="pre">time</span></tt> is unlimited so we don’t have to fix it.</p> +<p>We have 4 lidar channels so:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">channels</span><span class="o">=</span><span class="mi">4</span> +</pre></div> +</div> +<p>Regarding the dimension <tt class="docutils literal"><span class="pre">points</span></tt> we have only one channel with a +number of vertical bins equal to 3000 (the 1064nm) and all other +channels with 5000 vertical bins. In cases like this the dimension +<tt class="docutils literal"><span class="pre">points</span></tt> has to be fixed to the maximum number of vertical bins so:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">points</span><span class="o">=</span><span class="mi">5000</span> +</pre></div> +</div> +<p>Moreover only one channel (1064nm) is acquired with a time resolution of +30 seconds, all the other channels have a time resolution of 60 seconds. +This means that we have to define two different time scales. We have to +set:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">nb_of_time_scales</span><span class="o">=</span><span class="mi">2</span> +</pre></div> +</div> +<p>The measurement is performed only at one scan angle (5 degrees with +respect to the zenith) so:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">scan_angles</span><span class="o">=</span><span class="mi">1</span> +</pre></div> +</div> +<p>We have 3 minutes of dark measurements and two different time scales one +with 60 seconds time resolution and the other one with 30 seconds time +resolution. So we will have 3 different dark profiles for the channels +acquired with the first time scale and 6 for the lidar channels acquired +with the second time scale. We have to fix the dimension <tt class="docutils literal"><span class="pre">time_bck</span></tt> as +the maximum between these values:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">time_bck</span><span class="o">=</span><span class="mi">6</span> +</pre></div> +</div> +</div> +<div class="section" id="variables"> +<h3>Variables<a class="headerlink" href="#variables" title="Permalink to this headline">¶</a></h3> +<p>In this section it will be explained how to fill all the possible +variables either mandatory or optional of Raw Lidar Data input file.</p> +<dl class="docutils"> +<dt>Raw_Data_Start_Time(time, nb_of_time_scales)</dt> +<dd><p class="first">This 2 dimensional mandatory array has to contain the acquisition +start time (in seconds from the time given by the global attribute +<tt class="docutils literal"><span class="pre">RawData_Start_Time_UT</span></tt>) of each lidar profile. In this example we +have two different time scales: one is characterized by steps of 30 +seconds (the 1064nm is acquired with this time scale) the other by +steps of 60 seconds (532cross, 532parallel and 607nm). Moreover the +measurement start time is 00:00:01 UT and the measurement stop time +is 00:05:01 UT. In this case we have to define:</p> +<div class="highlight-python"><pre>Raw_Data_Start_Time = + 0, 0, + 60, 30, + 120, 60, + 180, 90, + 240, 120, + _, 150, + _, 180, + _, 210, + _, 240, + _, 270 ;</pre> +</div> +<p class="last">The order used to fill this array defines the correspondence between +the different time scales and the time scale index. In this example +we have a time scale index of 0 for the time scale with steps of 60 +seconds and a time scale index of 1 for the other one.</p> +</dd> +<dt>Raw_Data_Stop_Time(time, nb_of_time_scales)</dt> +<dd><p class="first">The same as previous item but for the data acquisition stop time. +Following a similar procedure we have to define:</p> +<div class="last highlight-python"><pre>Raw_Data_Stop_Time = + 60, 30, + 120, 60, + 180, 90, + 240, 120, + 300, 150, + _, 180, + _, 210, + _, 240, + _, 270, + _, 300 ;</pre> +</div> +</dd> +<dt>Raw_Lidar_Data(time, channels, points)</dt> +<dd><p class="first">This 3 dimensional mandatory array has to be filled with the +time-series of raw lidar data. The photoncounting profiles have to +submitted in counts (so as integers) while the analog ones in mV. The +order the user chooses to fill this array defines the correspondence +between channel index and lidar data.</p> +<p>For example if we fill this array in such way that:</p> +<table border="1" class="docutils"> +<colgroup> +<col width="38%" /> +<col width="62%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td>Raw_Lidar_Data(time,0,points</td> +<td><span class="math">\(\rightarrow\)</span> is the time-series of 1064 nm</td> +</tr> +<tr class="row-even"><td>Raw_Lidar_Data(time,1,points</td> +<td><span class="math">\(\rightarrow\)</span> is the time-series of 532 cross</td> +</tr> +<tr class="row-odd"><td>Raw_Lidar_Data(time,2,points</td> +<td><span class="math">\(\rightarrow\)</span> is the time-series of 532 parallel</td> +</tr> +<tr class="row-even"><td>Raw_Lidar_Data(time,3,points</td> +<td><span class="math">\(\rightarrow\)</span> is the time-series of 607 nm</td> +</tr> +</tbody> +</table> +<p class="last">from now on the channel index 0 is associated to the 1064 channel, +1 to the 532 cross, 2 to the 532 parallel and 3 to the 607nm.</p> +</dd> +<dt>Raw_Bck_Start_Time(time_bck, nb_of_time_scales)</dt> +<dd><p class="first">This 2 dimensional optional array has to contain the acquisition +start time (in seconds from the time given by the global attribute +<tt class="docutils literal"><span class="pre">RawBck_Start_Time_UT</span></tt>) of each dark measurements profile. +Following the same procedure used for the variable +<tt class="docutils literal"><span class="pre">Raw_Data_Start_Time</span></tt> we have to define:</p> +<div class="last highlight-python"><pre>Raw_Bck_Start_Time = + 0, 0, + 60, 30, + 120, 60, + _, 90, + _, 120, + _, 150;</pre> +</div> +</dd> +<dt>Raw_Bck_Stop_Time(time_bck, nb_of_time_scales)</dt> +<dd><p class="first">The same as previous item but for the dark acquisition stop time. +Following a similar procedure we have to define:</p> +<div class="last highlight-python"><pre>Raw_Bck_Stop_Time = + 60, 30, + 120, 60, + 180, 90, + _, 120, + _, 150, + _, 180 ;</pre> +</div> +</dd> +<dt>Background_Profile(time_bck, channels, points)</dt> +<dd><p class="first">This 3 dimensional optional array has to be filled with the +time-series of the dark measurements data. The photoncounting +profiles have to submitted in counts (so as integers) while the +analog ones in mV. The user has to fill this array following the same +order used in filling the array <tt class="docutils literal"><span class="pre">Raw_Lidar_Data</span></tt>:</p> +<table border="1" class="last docutils"> +<colgroup> +<col width="44%" /> +<col width="56%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td>Background_Profile(time_bck,0,points</td> +<td><span class="math">\(\rightarrow\)</span> dark time-series at 1064 nm</td> +</tr> +<tr class="row-even"><td>Background_Profile(time_bck,1,points</td> +<td><span class="math">\(\rightarrow\)</span> dark time-series at 532 cross</td> +</tr> +<tr class="row-odd"><td>Background_Profile(time_bck,2,points</td> +<td><span class="math">\(\rightarrow\)</span> dark time-series at 532 parallel</td> +</tr> +<tr class="row-even"><td>Background_Profile(time_bck,3,points</td> +<td><span class="math">\(\rightarrow\)</span> dark time-series at 607 nm</td> +</tr> +</tbody> +</table> +</dd> +<dt>channel_ID(channels)</dt> +<dd><p class="first">This mandatory array provides the link between the channel index +within the Raw Lidar Data input file and the channel ID in +SCC_DB. To fill this variable the user has to know which channel IDs +in SCC_DB correspond to his lidar channels. For this purpose the +SCC, in its final version will provide to the user a special tool to +get these channel IDs through a Web interface. At the moment this +interface is not yet available and these channel IDs will be +communicated directly to the user by the NA5 people.</p> +<p>Anyway to continue the example let’s suppose that the four lidar +channels taken into account are mapped into SCC_DB with the +following channel IDs:</p> +<table border="1" class="docutils"> +<colgroup> +<col width="30%" /> +<col width="70%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td>1064 nm</td> +<td><span class="math">\(\rightarrow\)</span> channel ID=7</td> +</tr> +<tr class="row-even"><td>532 cross</td> +<td><span class="math">\(\rightarrow\)</span> channel ID=5</td> +</tr> +<tr class="row-odd"><td>532 parallel</td> +<td><span class="math">\(\rightarrow\)</span> channel ID=6</td> +</tr> +<tr class="row-even"><td>607 nm</td> +<td><span class="math">\(\rightarrow\)</span> channel ID=8</td> +</tr> +</tbody> +</table> +<blockquote> +<div>In this case we have to define:</div></blockquote> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">channel_ID</span> <span class="o">=</span> <span class="mi">7</span><span class="p">,</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">6</span><span class="p">,</span> <span class="mi">8</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>id_timescale(channels)</dt> +<dd><p class="first">This mandatory array is introduced to determine which time scale is +used for the acquisition of each lidar channel. In particular this +array defines the link between the channel index and the time scale +index. In our example we have two different time scales. Filling the +arrays <tt class="docutils literal"><span class="pre">Raw_Data_Start_Time</span></tt> and <tt class="docutils literal"><span class="pre">Raw_Data_Stop_Time</span></tt> we have +defined a time scale index of 0 for the time scale with steps of 60 +seconds and a time scale index of 1 for the other one with steps of +30 seconds. In this way this array has to be set as:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">id_timescale</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Laser_Pointing_Angle(scan_angles</dt> +<dd><p class="first">This mandatory array contains all the scan angles used in the +measurement. In our example we have only one scan angle of 5 degrees +with respect to the zenith, so we have to define:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Laser_Pointing_Angle</span> <span class="o">=</span> <span class="mi">5</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Laser_Pointing_Angle_of_Profiles(time, nb_of_time_scales)</dt> +<dd><p class="first">This mandatory array is introduced to determine which scan angle is +used for the acquisition of each lidar profile. In particular this +array defines the link between the time and time scales indexes and +the scan angle index. In our example we have a single scan angle that +has to correspond to the scan angle index 0. So this array has to be +defined as:</p> +<div class="last highlight-python"><pre>Laser_Pointing_Angle_of_Profiles = + 0, 0, + 0, 0, + 0, 0, + 0, 0, + 0, 0, + _, 0, + _, 0, + _, 0, + _, 0, + _, 0 ;</pre> +</div> +</dd> +<dt>Laser_Shots(time, channels)</dt> +<dd><p class="first">This mandatory array stores the laser shots accumulated at each time +for each channel. In our example the number of laser shots +accumulated is 1500 for the 1064nm channels and 3000 for all the +other channels. Moreover the laser shots do not change with the time. +So we have to define this array as:</p> +<div class="last highlight-python"><pre>Laser_Shots = + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _ ;</pre> +</div> +</dd> +<dt>Emitted_Wavelength(channels)</dt> +<dd><p class="first">This optional array defines the link between the channel index and +the emission wavelength for each lidar channel. The wavelength has to +be expressed in nm. This information can be also taken from SCC_DB. +In our example we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Emitted_Wavelength</span> <span class="o">=</span> <span class="mi">1064</span><span class="p">,</span> <span class="mi">532</span><span class="p">,</span> <span class="mi">532</span><span class="p">,</span> <span class="mi">532</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Detected_Wavelength(channels)</dt> +<dd><p class="first">This optional array defines the link between the channel index and +the detected wavelength for each lidar channel. Here detected +wavelength means the value of center of interferential filter +expressed in nm. This information can be also taken from SCC_DB. In +our example we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Detected_Wavelength</span> <span class="o">=</span> <span class="mi">1064</span><span class="p">,</span> <span class="mi">532</span><span class="p">,</span> <span class="mi">532</span><span class="p">,</span> <span class="mi">607</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Raw_Data_Range_Resolution(channels)</dt> +<dd><p class="first">This optional array defines the link between the channel index and +the raw range resolution for each channel. If the scan angle is +different from zero this quantity is different from the vertical +resolution. More precisely if <span class="math">\(\alpha\)</span> is the scan angle used +and <span class="math">\(\Delta z\)</span> is the range resolution the vertical +resolution is calculated as <span class="math">\(\Delta +z'=\Delta z \cos\alpha\)</span>. This array has to be filled with +<span class="math">\(\Delta z\)</span> and not with <span class="math">\(\Delta z'\)</span>. The unit is +meters. This information can be also taken from SCC_DB. In our +example we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Raw_Data_Range_Resolution</span> <span class="o">=</span> <span class="mf">7.5</span><span class="p">,</span> <span class="mf">15.0</span><span class="p">,</span> <span class="mf">15.0</span><span class="p">,</span> <span class="mf">15.0</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>ID_Range(channels)</dt> +<dd><p class="first">This optional array defines if a particular channel is configured as +high, low or ultranear range channel. In particular a value 0 +indicates a low range channel, a value 1 a high range channel and a +value of 2 an ultranear range channel. If for a particular channel +you don’t separate between high and low range channel, please set the +corresponding value to 1. This information can be also taken from +SCC_DB. In our case we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">ID_Range</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Scattering_Mechanism(channels)</dt> +<dd><p class="first">This optional array defines the scattering mechanism involved in +each lidar channel. In particular the following values are adopted:</p> +<table border="1" class="docutils"> +<colgroup> +<col width="6%" /> +<col width="94%" /> +</colgroup> +<tbody valign="top"> +<tr class="row-odd"><td>0</td> +<td><span class="math">\(\rightarrow\)</span> Total elastic backscatter</td> +</tr> +<tr class="row-even"><td>1</td> +<td><span class="math">\(\rightarrow\)</span> <span class="math">\(N_2\)</span> vibrational Raman backscatter</td> +</tr> +<tr class="row-odd"><td>2</td> +<td><span class="math">\(\rightarrow\)</span> Cross polarization elastic backscatter</td> +</tr> +<tr class="row-even"><td>3</td> +<td><span class="math">\(\rightarrow\)</span> Parallel polarization elastic backscatter</td> +</tr> +<tr class="row-odd"><td>4</td> +<td><span class="math">\(\rightarrow\)</span> <span class="math">\(H_2O\)</span> vibrational Raman backscatter</td> +</tr> +<tr class="row-even"><td>5</td> +<td><span class="math">\(\rightarrow\)</span> Rotational Raman Stokes line close to elastic line</td> +</tr> +<tr class="row-odd"><td>6</td> +<td><span class="math">\(\rightarrow\)</span> Rotational Raman Stokes line far from elastic line</td> +</tr> +<tr class="row-even"><td>7</td> +<td><span class="math">\(\rightarrow\)</span> Rotational Raman anti-Stokes line close to elastic line</td> +</tr> +<tr class="row-odd"><td>8</td> +<td><span class="math">\(\rightarrow\)</span> Rotational Raman anti-Stokes line far from elastic line</td> +</tr> +<tr class="row-even"><td>9</td> +<td><span class="math">\(\rightarrow\)</span> Rotational Raman Stokes and anti-Stokes lines close to elastic line</td> +</tr> +<tr class="row-odd"><td>10</td> +<td><span class="math">\(\rightarrow\)</span> Rotational Raman Stokes and anti-Stokes lines far from elastic line</td> +</tr> +</tbody> +</table> +<p>This information can be also taken from SCC_DB. In our example we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Scattering_Mechanism</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">,</span> <span class="mi">1</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Acquisition_Mode(channels)</dt> +<dd><p class="first">This optional array defines the acquisition mode (analog or +photoncounting) involved in each lidar channel. In particular a value +of 0 means analog mode and 1 photoncounting mode. This information +can be also taken from SCC_DB. In our example we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Acquisition_Mode</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Laser_Repetition_Rate(channels)</dt> +<dd><p class="first">This optional array defines the repetition rate in Hz used to +acquire each lidar channel. This information can be also taken from +SCC_DB. In our example we are supposing we have only one laser with +a repetition rate of 50 Hz so we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Laser_Repetition_Rate</span> <span class="o">=</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">50</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Dead_Time(channels)</dt> +<dd><p class="first">This optional array defines the dead time in ns associated to each +lidar channel. The SCC will use the values given by this array to +correct the photoncounting signals for dead time. Of course for +analog signals no dead time correction will be applied (for analog +channels the corresponding dead time values have to be set to +undefined value). This information can be also taken from SCC_DB. In +our example the 1064 nm channel is acquired in analog mode so the +corresponding dead time value has to be undefined. If we suppose a +dead time of 10 ns for all other channels we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Dead_Time</span> <span class="o">=</span> <span class="n">_</span><span class="p">,</span> <span class="mi">10</span><span class="p">,</span> <span class="mi">10</span><span class="p">,</span> <span class="mi">10</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Dead_Time_Corr_Type(channels</dt> +<dd><p class="first">This optional array defines which kind of dead time correction has +to be applied on each photoncounting channel. The SCC will correct +the data supposing a not-paralyzable channel if a value of 0 is found +while a paralyzable channel is supposed if a value of 1 is found. Of +course for analog signals no dead time correction will be applied and +so the corresponding values have to be set to undefined value. This +information can be also taken from SCC_DB. In our example the 1064 +nm channel is acquired in analog mode so the corresponding has to be +undefined. If we want to consider all the photoncounting signals as +not-paralyzable ones: we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Dead_Time_Corr_Type</span> <span class="o">=</span> <span class="n">_</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Trigger_Delay(channels)</dt> +<dd><p class="first">This optional array defines the delay (in ns) of the middle of the +first rangebin with respect to the output laser pulse for each lidar +channel. The SCC will use the values given by this array to correct +for trigger delay. This information can be also taken from SCC_DB. +Let’s suppose that in our example all the photoncounting channels are +not affected by this delay and only the analog channel at 1064nm is +acquired with a delay of 50ns. In this case we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Trigger_Delay</span> <span class="o">=</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Background_Mode(channels</dt> +<dd><p class="first">This optional array defines how the atmospheric background has to be +subtracted from the lidar channel. Two options are available for the +calculation of atmospheric background:</p> +<ol class="arabic simple"> +<li>Average in the far field of lidar channel. In this case the value +of this variable has to be 1</li> +<li>Average within pre-trigger bins. In this case the value of this +variable has to be 0</li> +</ol> +<p>This information can be also taken from SCC_DB. Let’s suppose in our +example we use the pre-trigger for the 1064nm channel and the far +field for all other channels. In this case we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Background_Mode</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">1</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Background_Low(channels)</dt> +<dd><p class="first">This mandatory array defines the minimum altitude (in meters) to +consider in calculating the atmospheric background for each channel. +In case pre-trigger mode is used the corresponding value has to be +set to the rangebin to be used as lower limit (within pre-trigger +region) for background calculation. In our example, if we want to +calculate the background between 30000 and 50000 meters for all +photoncounting channels and we want to use the first 500 pre-trigger +bins for the background calculation for the 1064nm channel we have to +set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Background_Low</span><span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">30000</span><span class="p">,</span> <span class="mi">30000</span><span class="p">,</span> <span class="mi">30000</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Background_High(channels)</dt> +<dd><p class="first">This mandatory array defines the maximum altitude (in meters) to +consider in calculating the atmospheric background for each channel. +In case pre-trigger mode is used the corresponding value has to be +set to the rangebin to be used as upper limit (within pre-trigger +region) for background calculation. In our example, if we want to +calculate the background between 30000 and 50000 meters for all +photoncounting channels and we want to use the first 500 pre-trigger +bins for the background calculation for the 1064nm channel we have to +set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Background_High</span> <span class="o">=</span> <span class="mi">500</span><span class="p">,</span> <span class="mi">50000</span><span class="p">,</span> <span class="mi">50000</span><span class="p">,</span> <span class="mi">50000</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Molecular_Calc</dt> +<dd><p class="first">This mandatory variable defines the way used by SCC to calculate the +molecular density profile. At the moment two options are available:</p> +<ol class="arabic simple"> +<li>US Standard Atmosphere 1976. In this case the value of this +variable has to be 0</li> +<li>Radiosounding. In this case the value of this variable has to be 1</li> +</ol> +<p>If we decide to use the option 1. we have to provide also the +measured pressure and temperature at lidar station level. Indeed if +we decide to use the option 2. a radiosounding file has to be +submitted separately in NetCDF format (the structure of this file is +summarized in table tab:sounding). Let’s suppose we want to use the +option 1. so:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Molecular_Calc</span> <span class="o">=</span> <span class="mi">0</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Pressure_at_Lidar_Station</dt> +<dd><p class="first">Because we have chosen the US Standard Atmosphere for calculation of +the molecular density profile we have to give the pressure in hPa at +lidar station level:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Pressure_at_Lidar_Station</span> <span class="o">=</span> <span class="mi">1010</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Temperature_at_Lidar_Station</dt> +<dd><p class="first">Because we have chosen the US Standard Atmosphere for calculation of +the molecular density profile we have to give the temperature in C at +lidar station level:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Temperature_at_Lidar_Station</span> <span class="o">=</span> <span class="mf">19.8</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>Depolarization_Factor(channels)</dt> +<dd><p class="first">This array is required only for lidar systems that use the two +depolarization channels for the backscatter retrieval. It represents +the factor <span class="math">\(f\)</span> to calculate the total backscatter signal +<span class="math">\(S_t\)</span> combining its cross <span class="math">\(S_c\)</span> and parallel +<span class="math">\(S_p\)</span> components: <span class="math">\(S_t=S_p+fS_c\)</span>. This factor is +mandatory only for systems acquiring <span class="math">\(S_c\)</span> and <span class="math">\(S_p\)</span> +and not <span class="math">\(S_t\)</span>. For systems acquiring <span class="math">\(S_c\)</span>, +<span class="math">\(S_p\)</span> and <span class="math">\(S_t\)</span> this factor is optional and it will +be used only for depolarizaton ratio calculation. Moreover only the +values of the array corresponding to cross polarization channels will +be considered; all other values will be not taken into account and +should be set to undefined value. In our example for the wavelength +532nm we have only the cross and the parallel components and not the +total one. So we have to give the value of this factor only in +correspondence of the 532nm cross polarization channel that +corresponds to the channel index 1. Suppose that this factor is 0.88. +Moreover, because we don’t have any other depolarization channels we +have also to set all other values of the array to undefined value.</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Depolarization_Factor</span> <span class="o">=</span> <span class="n">_</span><span class="p">,</span><span class="mf">0.88</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>LR_Input(channels)</dt> +<dd><p class="first">This array is required only for lidar channels for which elastic +backscatter retrieval has to be performed. It defines the lidar ratio +to be used within this retrieval. Two options are available:</p> +<ol class="arabic simple"> +<li>The user can submit a lidar ratio profile. In this case the value +of this variable has to be 0.</li> +<li>A fixed value of lidar ratio can be used. In this case the value +of this variable has to be 1.</li> +</ol> +<p>If we decide to use the option 1. a lidar ratio file has to be +submitted separately in NetCDF format (the structure of this file is +summarized in table tab:lr). If we decide to use the option 2. the +fixed value of lidar ratio will be taken from SCC_DB. In our example +we have to give a value of this array only for the 1064nm lidar +channel because for the 532nm we will be able to retrieve a Raman +backscatter coefficient. In case we want to use the fixed value +stored in SCC_DB we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">LR_Input</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>DAQ_Range(channels)</dt> +<dd><p class="first">This array is required only if one or more lidar signals are +acquired in analog mode. It gives the analog scale in mV used to +acquire the analog signals. In our example we have only the 1064nm +channel acquired in analog mode. If we have used a 100mV analog scale +to acquire this channel we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">DAQ_Range</span> <span class="o">=</span> <span class="mi">100</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +</dl> +</div> +<div class="section" id="global-attributes"> +<h3>Global attributes<a class="headerlink" href="#global-attributes" title="Permalink to this headline">¶</a></h3> +<dl class="docutils"> +<dt>Measurement_ID</dt> +<dd><p class="first">This mandatory global attribute defines the measurement ID +corresponding to the actual lidar measurement. It is a string +composed by 12 characters. The first 8 characters give the start date +of measurement in the format YYYYMMDD. The next 2 characters give the +Earlinet call-sign of the station. The last 2 characters are used to +distinguish between different time-series within the same date. In +our example we have to set:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">Measurement_ID</span><span class="o">=</span> <span class="s">"20090130cc00"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>RawData_Start_Date</dt> +<dd><p class="first">This mandatory global attribute defines the start date of lidar +measurements in the format YYYYMMDD. In our case we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">RawData_Start_Date</span> <span class="o">=</span> <span class="s">"20090130"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>RawData_Start_Time_UT</dt> +<dd><p class="first">This mandatory global attribute defines the UT start time of lidar +measurements in the format HHMMSS. In our case we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">RawData_Start_Time_UT</span> <span class="o">=</span> <span class="s">"000001"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>RawData_Stop_Time_UT``</dt> +<dd><p class="first">This mandatory global attribute defines the UT stop time of lidar +measurements in the format HHMMSS. In our case we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">RawData_Stop_Time_UT</span> <span class="o">=</span> <span class="s">"000501"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>RawBck_Start_Date</dt> +<dd><p class="first">This optional global attribute defines the start date of dark +measurements in the format YYYYMMDD. In our case we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">RawBck_Start_Date</span> <span class="o">=</span> <span class="s">"20090129"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>RawBck_Start_Time_UT</dt> +<dd><p class="first">This optional global attribute defines the UT start time of dark +measurements in the format HHMMSS. In our case we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">RawBck_Start_Time_UT</span> <span class="o">=</span> <span class="s">"235001"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +<dt>RawBck_Stop_Time_UT</dt> +<dd><p class="first">This optional global attribute defines the UT stop time of dark +measurements in the format HHMMSS. In our case we have:</p> +<div class="last highlight-python"><div class="highlight"><pre><span class="n">RawBck_Stop_Time_UT</span> <span class="o">=</span> <span class="s">"235301"</span> <span class="p">;</span> +</pre></div> +</div> +</dd> +</dl> +</div> +</div> +<div class="section" id="example-of-file-cdl-format"> +<h2>Example of file (CDL format)<a class="headerlink" href="#example-of-file-cdl-format" title="Permalink to this headline">¶</a></h2> +<p>To summarize we have the following NetCDF Raw Lidar Data file (in CDL +format):</p> +<div class="highlight-python"><pre>dimensions: + points = 5000 ; + channels = 4 ; + time = UNLIMITED ; // (10 currently) + nb_of_time_scales = 2 ; + scan_angles = 1 ; + time_bck = 6 ; +variables: + int channel_ID(channels) ; + int Laser_Repetition_Rate(channels) ; + double Laser_Pointing_Angle(scan_angles) ; + int ID_Range(channels) ; + int Scattering_Mechanism(channels) ; + double Emitted_Wavelength(channels) ; + double Detected_Wavelength(channels) ; + double Raw_Data_Range_Resolution(channels) ; + int Background_Mode(channels) ; + double Background_Low(channels) ; + double Background_High(channels) ; + int Molecular_Calc ; + double Pressure_at_Lidar_Station ; + double Temperature_at_Lidar_Station ; + int id_timescale(channels) ; + double Dead_Time(channels) ; + int Dead_Time_Corr_Type(channels) ; + int Acquisition_Mode(channels) ; + double Trigger_Delay(channels) ; + int LR_Input(channels) ; + int Laser_Pointing_Angle_of_Profiles(time, nb_of_time_scales) ; + int Raw_Data_Start_Time(time, nb_of_time_scales) ; + int Raw_Data_Stop_Time(time, nb_of_time_scales) ; + int Raw_Bck_Start_Time(time_bck, nb_of_time_scales) ; + int Raw_Bck_Stop_Time(time_bck, nb_of_time_scales) ; + int Laser_Shots(time, channels) ; + double Raw_Lidar_Data(time, channels, points) ; + double Background_Profile(time_bck, channels, points) ; + double DAQ_Range(channels) ; + +// global attributes: + :Measurement_ID = "20090130cc00" ; + :RawData_Start_Date = "20090130" ; + :RawData_Start_Time_UT = "000001" ; + :RawData_Stop_Time_UT = "000501" ; + :RawBck_Start_Date = "20090129" ; + :RawBck_Start_Time_UT = "235001" ; + :RawBck_Stop_Time_UT = "235301" ; + +data: + + channel_ID = 7, 5, 6, 8 ; + + Laser_Repetition_Rate = 50, 50, 50, 50 ; + + Laser_Pointing_Angle = 5 ; + + ID_Range = 1, 1, 1, 1 ; + + Scattering_Mechanism = 0, 2, 3, 1 ; + + Emitted_Wavelength = 1064, 532, 532, 532 ; + + Detected_Wavelength = 1064, 532, 532, 607 ; + + Raw_Data_Range_Resolution = 7.5, 15, 15, 15 ; + + Background_Mode = 0, 1, 1, 1 ; + + Background_Low = 0, 30000, 30000, 30000 ; + + Background_High = 500, 50000, 50000, 50000 ; + + Molecular_Calc = 0 ; + + Pressure_at_Lidar_Station = 1010 ; + + Temperature_at_Lidar_Station = 19.8 ; + + id_timescale = 1, 0, 0, 0 ; + + Dead_Time = _, 10, 10, 10 ; + + Dead_Time_Corr_Type = _, 0, 0, 0 ; + + Acquisition_Mode = 0, 1, 1, 1 ; + + Trigger_Delay = 50, 0, 0, 0 ; + + LR_Input = 1,_,_,_ ; + + DAQ_Range = 100,_,_,_ ; + + Laser_Pointing_Angle_of_Profiles = + 0, 0, + 0, 0, + 0, 0, + 0, 0, + 0, 0, + _, 0, + _, 0, + _, 0, + _, 0, + _, 0 ; + + + Raw_Data_Start_Time = + 0, 0, + 60, 30, + 120, 60, + 180, 90, + 240, 120, + _, 150, + _, 180, + _, 210, + _, 240, + _, 270 ; + + Raw_Data_Stop_Time = + 60, 30, + 120, 60, + 180, 90, + 240, 120, + 300, 150, + _, 180, + _, 210, + _, 240, + _, 270, + _, 300 ; + + + Raw_Bck_Start_Time = + 0, 0, + 60, 30, + 120, 60, + _, 90, + _, 120, + _, 150; + + +Raw_Bck_Stop_Time = + 60, 30, + 120, 60, + 180, 90, + _, 120, + _, 150, + _, 180 ; + + + Laser_Shots = + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _ ; + + + Raw_Lidar_Data = ... + + Background_Profile = ...</pre> +</div> +<p>Please keep in mind that in case you submit a file like the previous one +all the parameters present in it will be used by the SCC even if you +have different values for the same parameters within the SCC_DB. If you +want to use the values already stored in SCC_DB (this should be the +usual way to use SCC) the Raw Lidar Data input file has to be +modified as follows:</p> +<div class="highlight-python"><pre>dimensions: + points = 5000 ; + channels = 4 ; + time = UNLIMITED ; // (10 currently) + nb_of_time_scales = 2 ; + scan_angles = 1 ; + time_bck = 6 ; +variables: + int channel_ID(channels) ; + double Laser_Pointing_Angle(scan_angles) ; + double Background_Low(channels) ; + double Background_High(channels) ; + int Molecular_Calc ; + double Pressure_at_Lidar_Station ; + double Temperature_at_Lidar_Station ; + int id_timescale(channels) ; + int Laser_Pointing_Angle_of_Profiles(time, nb_of_time_scales) ; + int Raw_Data_Start_Time(time, nb_of_time_scales) ; + int Raw_Data_Stop_Time(time, nb_of_time_scales) ; + int Raw_Bck_Start_Time(time_bck, nb_of_time_scales) ; + int Raw_Bck_Stop_Time(time_bck, nb_of_time_scales) ; + int LR_Input(channels) ; + int Laser_Shots(time, channels) ; + double Raw_Lidar_Data(time, channels, points) ; + double Background_Profile(time_bck, channels, points) ; + double DAQ_Range(channels) ; + +// global attributes: + :Measurement_ID = "20090130cc00" ; + :RawData_Start_Date = "20090130" ; + :RawData_Start_Time_UT = "000001" ; + :RawData_Stop_Time_UT = "000501" ; + :RawBck_Start_Date = "20090129" ; + :RawBck_Start_Time_UT = "235001" ; + :RawBck_Stop_Time_UT = "235301" ; + +data: + + channel_ID = 7, 5, 6, 8 ; + + Laser_Pointing_Angle = 5 ; + + Background_Low = 0, 30000, 30000, 30000 ; + + Background_High = 500, 50000, 50000, 50000 ; + + Molecular_Calc = 0 ; + + Pressure_at_Lidar_Station = 1010 ; + + Temperature_at_Lidar_Station = 19.8 ; + + id_timescale = 1, 0, 0, 0 ; + + LR_Input = 1,_,_,_ ; + + DAQ_Range = 100,_,_,_ ; + + Laser_Pointing_Angle_of_Profiles = + 0, 0, + 0, 0, + 0, 0, + 0, 0, + 0, 0, + _, 0, + _, 0, + _, 0, + _, 0, + _, 0 ; + + + Raw_Data_Start_Time = + 0, 0, + 60, 30, + 120, 60, + 180, 90, + 240, 120, + _, 150, + _, 180, + _, 210, + _, 240, + _, 270 ; + + Raw_Data_Stop_Time = + 60, 30, + 120, 60, + 180, 90, + 240, 120, + 300, 150, + _, 180, + _, 210, + _, 240, + _, 270, + _, 300 ; + + + Raw_Bck_Start_Time = + 0, 0, + 60, 30, + 120, 60, + _, 90, + _, 120, + _, 150; + + + Raw_Bck_Stop_Time = + 60, 30, + 120, 60, + 180, 90, + _, 120, + _, 150, + _, 180 ; + + + Laser_Shots = + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, 3000, 3000, 3000, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _, + 1500, _, _, _ ; + + + Raw_Lidar_Data = ... + + Background_Profile = ...</pre> +</div> +<p>This example file contains the minimum collection of mandatory +information that has to be found within the Raw Lidar Data input +file. If it is really necessary, the user can decide to add to these +mandatory parameters any number of additional parameters considered in +the previous example.</p> +<p>Finally, suppose we want to make the following changes with respect to +the previous example:</p> +<ol class="arabic simple"> +<li>use a sounding file for molecular density calculation instead of “US +Standar Atmosphere 1976”</li> +<li>supply a lidar ratio profile to use in elastic backscatter retrieval +instead of a fixed value</li> +<li>provide a overlap function for overlap correction</li> +</ol> +<p>In this case we have to generate the following NetCDF additional files:</p> +<dl class="docutils"> +<dt>rs_20090130cc00.nc</dt> +<dd>The name of Sounding Data file has to be computed as follows: +<tt class="docutils literal"><span class="pre">"rs_"``+``Measurement_ID</span></tt> +The structure of this file is summarized in table tab:sounding.</dd> +<dt>ov_20090130cc00.nc</dt> +<dd>The name of Overlap file has to be computed as follows: +<tt class="docutils literal"><span class="pre">"ov_"``+``Measurement_ID</span></tt> +The structure of this file is summarized in table tab:overlap.</dd> +<dt>lr_20090130cc00.nc</dt> +<dd>The name of Lidar Ratio file has to be computed as follows: +<tt class="docutils literal"><span class="pre">"lr_"``+``Measurement_ID</span></tt> +The structure of this file is summarized in table tab:lr.</dd> +</dl> +<p>Moreover we need to apply the following changes to the Raw Lidar Data +input file:</p> +<ol class="arabic"> +<li><p class="first">Change the value of the variable <tt class="docutils literal"><span class="pre">Molecular_Calc</span></tt> as follows:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">Molecular_Calc</span> <span class="o">=</span> <span class="mi">1</span> <span class="p">;</span> +</pre></div> +</div> +<p>Of course the variables <tt class="docutils literal"><span class="pre">Pressure_at_Lidar_Station</span></tt> and +<tt class="docutils literal"><span class="pre">Temperature_at_Lidar_Station</span></tt> are not necessary anymore.</p> +</li> +<li><p class="first">Change the values of the array <tt class="docutils literal"><span class="pre">LR_Input</span></tt> as follows:</p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">LR_Input</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span><span class="p">,</span><span class="n">_</span> <span class="p">;</span> +</pre></div> +</div> +</li> +<li><p class="first">Add the global attribute <tt class="docutils literal"><span class="pre">Sounding_File_Name</span></tt></p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">Sounding_File_Name</span> <span class="o">=</span> <span class="s">"rs_20090130cc00.nc"</span> <span class="p">;</span> +</pre></div> +</div> +</li> +</ol> +<ol class="arabic" start="5"> +<li><p class="first">Add the global attribute <tt class="docutils literal"><span class="pre">LR_File_Name</span></tt></p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">LR_File_Name</span> <span class="o">=</span> <span class="s">"lr_20090130cc00.nc"</span> <span class="p">;</span> +</pre></div> +</div> +</li> +<li><p class="first">Add the global attribute <tt class="docutils literal"><span class="pre">Overlap_File_Name</span></tt></p> +<div class="highlight-python"><div class="highlight"><pre><span class="n">Overlap_File_Name</span> <span class="o">=</span> <span class="s">"ov_20090130cc00.nc"</span> <span class="p">;</span> +</pre></div> +</div> +</li> +</ol> +</div> +</div> + + + </div> + </div> + </div> + <div class="sphinxsidebar"> + <div class="sphinxsidebarwrapper"> + <h3><a href="index.html">Table Of Contents</a></h3> + <ul> +<li><a class="reference internal" href="#">The SCC netCDF file format</a><ul> +<li><a class="reference internal" href="#rationale">Rationale</a></li> +<li><a class="reference internal" href="#example">Example</a><ul> +<li><a class="reference internal" href="#dimensions">Dimensions</a></li> +<li><a class="reference internal" href="#variables">Variables</a></li> +<li><a class="reference internal" href="#global-attributes">Global attributes</a></li> +</ul> +</li> +<li><a class="reference internal" href="#example-of-file-cdl-format">Example of file (CDL format)</a></li> +</ul> +</li> +</ul> + + <h4>Previous topic</h4> + <p class="topless"><a href="measurement_upload.html" + title="previous chapter">Processing measurement</a></p> + <h4>Next topic</h4> + <p class="topless"><a href="user_managment.html" + title="next chapter">User management</a></p> + <h3>This Page</h3> + <ul class="this-page-menu"> + <li><a href="_sources/netcdf_file.txt" + rel="nofollow">Show Source</a></li> + </ul> +<div id="searchbox" style="display: none"> + <h3>Quick search</h3> + <form class="search" action="search.html" method="get"> + <input type="text" name="q" /> + <input type="submit" value="Go" /> + <input type="hidden" name="check_keywords" value="yes" /> + <input type="hidden" name="area" value="default" /> + </form> + <p class="searchtip" style="font-size: 90%"> + Enter search terms or a module, class or function name. + </p> +</div> +<script type="text/javascript">$('#searchbox').show(0);</script> + </div> + </div> + <div class="clearer"></div> + </div> + <div class="related"> + <h3>Navigation</h3> + <ul> + <li class="right" style="margin-right: 10px"> + <a href="genindex.html" title="General Index" + >index</a></li> + <li class="right" > + <a href="user_managment.html" title="User management" + >next</a> |</li> + <li class="right" > + <a href="measurement_upload.html" title="Processing measurement" + >previous</a> |</li> + <li><a href="index.html">Single Calculus Chain 0.2 documentation</a> »</li> + </ul> + </div> + <div class="footer"> + © Copyright 2012, SCC team. + Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.1.2. + </div> + </body> +</html> \ No newline at end of file