Mercurial > public > sccdocs / changeset

--- a/docs/faq/faq.rst	Wed Feb 20 15:24:19 2013 +0100
+++ b/docs/faq/faq.rst	Fri Mar 01 13:18:31 2013 +0100
@@ -4,8 +4,8 @@
 Clouds in the data
 ~~~~~~~~~~~~~~~~~~
 
-Q: Is it necessary to provide only measurment periods with cloud free conditions and 
-homogeneous atmosphere or is this part of ELDA or the pre processing of the data? 
+Q: Is it necessary to provide only measurement periods with cloud free conditions and 
+homogeneous atmosphere or is this part of ELDA or the pre-processing of the data? 
 For example in cases with scattered low cumulus clouds.
 
 A: At moment you should provide cloud free data because the automatic cloud screening 
@@ -26,7 +26,7 @@
 Variable depolarization factor
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Q: Due to changes in the settings of our lidarsystem, the depolarization factor can 
+Q: Due to changes in the settings of our lidar system, the depolarization factor can 
 change during the measurement. Is it necessary to provide one SCC-file for each settings 
 or is it possible to set the Depolarization_Factor variable time dependent? 
    
@@ -60,8 +60,8 @@
 you should set LR_Input accordingly and provide an external LR profile NetCDF file 
 (see documentation on SCC file format).
 
-Calculation of raman and elastic backsatter
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Calculation of Raman and elastic backscatter
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Q: In cases of measurements where Raman channels are available, the SCC will calculate the Raman 
 backscatter profile. If I want to retrieve Klett-retrievals for this channel, too (e.g 532nm) 
 is it sufficient to set the value in LR_input(channels) to 1 or 0 plus a LR-profile to get 
@@ -85,34 +85,71 @@
 
 Filename conventions
 ~~~~~~~~~~~~~~~~~~~~
-A: What are the conventions for the filnames for the various files that need to be uploaded?
+A: What are the conventions for the filenames for the various files that need to be uploaded?
 
 Q: The following definitions apply:   
-- SCC raw lidar data file
 
-This file should be named as measID.nc. For example if your measurement had a measurementID of 20130101cc00 the corresponding NetCDF file should be named 20130101cc00.nc 
+SCC raw lidar data file
+^^^^^^^^^^^^^^^^^^^^^^^
+
+This file should be named as measID.nc. For example if your measurement had a measurement ID of 20130101cc00 the corresponding NetCDF file should be named 20130101cc00.nc 
 
 Sounding file
 ^^^^^^^^^^^^^
 
 The file should be named as rs_measID.nc. Considering the above example the sounding file should be named rs_20130101cc00.nc
 
-In this case you should also set the global attribute Sounding_File_Name in the raw lidar data file as:
+In this case you should also set the global attribute Sounding_File_Name in the raw lidar data file as::
 
-Sounding_File_Name=rs_20130101cc00.nc
+   Sounding_File_Name=rs_20130101cc00.nc
 
 Lidar ratio file
 ^^^^^^^^^^^^^^^^
 The file should be named as lr_measID.nc. Considering the above example the sounding file should be named lr_20130101cc00.nc
 
-In this case you should also set the global attribute LR_File_Name in the raw lidar data file as:
+In this case you should also set the global attribute LR_File_Name in the raw lidar data file as::
 
-LR_File_Name=lr_20130101cc00.nc
+   LR_File_Name=lr_20130101cc00.nc
 
 Overlap file
 ^^^^^^^^^^^^
 The file should be named as ov_measID.nc. Considering the above example the sounding file should be named ov_20130101cc00.nc
 
-In this case you should also set the global attribute Overlap_File_Name in the raw lidar data file as:
+In this case you should also set the global attribute Overlap_File_Name in the raw lidar data file as::
+
+   Overlap_File_Name=ov_20130101cc00.nc
+
+
+Photocounting values should be integers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Q: In one of my measurements I get an error concerning the photoncounting values::
+
+   Pre processing (177): Found no integer values in photoncounting signal
+
+The Raw_Lidar_Data variable in the NetCDF-file is defined as double. So is it necessary for Photoncounting signals to only provide integer values?
+
+A: Two important considerations:
 
-Overalp_File_Name=ov_20130101cc00.nc
+1. The Raw_Lidar_Data array should contain your *real* raw data. 
+   This means that *no corrections/operations* should be made on your signals 
+   before filling the Raw_Lidar_Data array. This is particularly important because *all* 
+   the operations and corrections should be applied by the SCC and not by the user before 
+   the submission. In this way we can keep track of all the operations made on the signals 
+   (for QA purposes) and moreover we are sure that all the corrections are applied in a 
+   correct order  (this is particularly important for non linear operations, think for example to the dead time correction).
+
+2. The analog signals should be expressed in mV and the photoncounting signals in raw counts
+
+So if your photoncounting values are not integers they are not expressed in raw counts (which of course should be integers). 
+So the point here is not how to convert them in integers but to submit the right quantity in the right units.
+
+So please check carefully your converter and be sure to really submit raw counts for photoncounting channels and raw mV for the analog ones.
+
+
+Preprocessing failed but no Exit code is provided
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Q: The preprocessing of one of my measurements failed (I get a status -127). However, when I check the Exit codes 
+to see the description of the problem, I get an empty value (-). What does this mean?
+
+A: This means that the preprocessor crushed unexpectedly! Sorry for that! Report the problem in the forum and it will be fixed 
+soon.