# HG changeset patch # User ulalume3 # Date 1362140311 -3600 # Node ID 44196e354b52333a30b4d1d73b70b8741caed879 # Parent c426a3e4b62c44944a05f2c90ace399daff40080 New questions added in the FAQ diff -r c426a3e4b62c -r 44196e354b52 docs/faq/faq.rst --- 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.