comparison: docs/faq/faq.rst
docs/faq/faq.rst
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| 2 ========================== | 2 ========================== |
| 3 | 3 |
| 4 Clouds in the data | 4 Clouds in the data |
| 5 ~~~~~~~~~~~~~~~~~~ | 5 ~~~~~~~~~~~~~~~~~~ |
| 6 | 6 |
| 7 Q: Is it necessary to provide only measurment periods with cloud free conditions and | 7 Q: Is it necessary to provide only measurement periods with cloud free conditions and |
| 8 homogeneous atmosphere or is this part of ELDA or the pre processing of the data? | 8 homogeneous atmosphere or is this part of ELDA or the pre-processing of the data? |
| 9 For example in cases with scattered low cumulus clouds. | 9 For example in cases with scattered low cumulus clouds. |
| 10 | 10 |
| 11 A: At moment you should provide cloud free data because the automatic cloud screening | 11 A: At moment you should provide cloud free data because the automatic cloud screening |
| 12 is not yet implemented in the SCC. We are working on this issue and hopefully the new | 12 is not yet implemented in the SCC. We are working on this issue and hopefully the new |
| 13 module will be implemented at the end of ACTRIS project . | 13 module will be implemented at the end of ACTRIS project . |
| 24 id flags are not taken into account. | 24 id flags are not taken into account. |
| 25 | 25 |
| 26 Variable depolarization factor | 26 Variable depolarization factor |
| 27 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | 27 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 28 | 28 |
| 29 Q: Due to changes in the settings of our lidarsystem, the depolarization factor can | 29 Q: Due to changes in the settings of our lidar system, the depolarization factor can |
| 30 change during the measurement. Is it necessary to provide one SCC-file for each settings | 30 change during the measurement. Is it necessary to provide one SCC-file for each settings |
| 31 or is it possible to set the Depolarization_Factor variable time dependent? | 31 or is it possible to set the Depolarization_Factor variable time dependent? |
| 32 | 32 |
| 33 A: Unfortunately it is not possible to have time dependence on Depolarization_Factor variable. | 33 A: Unfortunately it is not possible to have time dependence on Depolarization_Factor variable. |
| 34 So if this parameter changes you should provide different SCC files for each setting. | 34 So if this parameter changes you should provide different SCC files for each setting. |
| 58 each elastic backscatter product: in the product page there is the section "Elastic Backscatter | 58 each elastic backscatter product: in the product page there is the section "Elastic Backscatter |
| 59 options" in which there is the field "Fixed lr". In case you want to use a lidar ratio profile | 59 options" in which there is the field "Fixed lr". In case you want to use a lidar ratio profile |
| 60 you should set LR_Input accordingly and provide an external LR profile NetCDF file | 60 you should set LR_Input accordingly and provide an external LR profile NetCDF file |
| 61 (see documentation on SCC file format). | 61 (see documentation on SCC file format). |
| 62 | 62 |
| 63 Calculation of raman and elastic backsatter | 63 Calculation of Raman and elastic backscatter |
| 64 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | 64 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 65 Q: In cases of measurements where Raman channels are available, the SCC will calculate the Raman | 65 Q: In cases of measurements where Raman channels are available, the SCC will calculate the Raman |
| 66 backscatter profile. If I want to retrieve Klett-retrievals for this channel, too (e.g 532nm) | 66 backscatter profile. If I want to retrieve Klett-retrievals for this channel, too (e.g 532nm) |
| 67 is it sufficient to set the value in LR_input(channels) to 1 or 0 plus a LR-profile to get | 67 is it sufficient to set the value in LR_input(channels) to 1 or 0 plus a LR-profile to get |
| 68 both retrievals? | 68 both retrievals? |
| 69 | 69 |
| 83 Moreover in general, it makes no sense to calculate the elastic backscatter when you can calculate the Raman | 83 Moreover in general, it makes no sense to calculate the elastic backscatter when you can calculate the Raman |
| 84 one which usually is better. | 84 one which usually is better. |
| 85 | 85 |
| 86 Filename conventions | 86 Filename conventions |
| 87 ~~~~~~~~~~~~~~~~~~~~ | 87 ~~~~~~~~~~~~~~~~~~~~ |
| 88 A: What are the conventions for the filnames for the various files that need to be uploaded? | 88 A: What are the conventions for the filenames for the various files that need to be uploaded? |
| 89 | 89 |
| 90 Q: The following definitions apply: | 90 Q: The following definitions apply: |
| 91 - SCC raw lidar data file | |
| 92 | 91 |
| 93 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 | 92 SCC raw lidar data file |
| 93 ^^^^^^^^^^^^^^^^^^^^^^^ | |
| 94 | |
| 95 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 | |
| 94 | 96 |
| 95 Sounding file | 97 Sounding file |
| 96 ^^^^^^^^^^^^^ | 98 ^^^^^^^^^^^^^ |
| 97 | 99 |
| 98 The file should be named as rs_measID.nc. Considering the above example the sounding file should be named rs_20130101cc00.nc | 100 The file should be named as rs_measID.nc. Considering the above example the sounding file should be named rs_20130101cc00.nc |
| 99 | 101 |
| 100 In this case you should also set the global attribute Sounding_File_Name in the raw lidar data file as: | 102 In this case you should also set the global attribute Sounding_File_Name in the raw lidar data file as:: |
| 101 | 103 |
| 102 Sounding_File_Name=rs_20130101cc00.nc | 104 Sounding_File_Name=rs_20130101cc00.nc |
| 103 | 105 |
| 104 Lidar ratio file | 106 Lidar ratio file |
| 105 ^^^^^^^^^^^^^^^^ | 107 ^^^^^^^^^^^^^^^^ |
| 106 The file should be named as lr_measID.nc. Considering the above example the sounding file should be named lr_20130101cc00.nc | 108 The file should be named as lr_measID.nc. Considering the above example the sounding file should be named lr_20130101cc00.nc |
| 107 | 109 |
| 108 In this case you should also set the global attribute LR_File_Name in the raw lidar data file as: | 110 In this case you should also set the global attribute LR_File_Name in the raw lidar data file as:: |
| 109 | 111 |
| 110 LR_File_Name=lr_20130101cc00.nc | 112 LR_File_Name=lr_20130101cc00.nc |
| 111 | 113 |
| 112 Overlap file | 114 Overlap file |
| 113 ^^^^^^^^^^^^ | 115 ^^^^^^^^^^^^ |
| 114 The file should be named as ov_measID.nc. Considering the above example the sounding file should be named ov_20130101cc00.nc | 116 The file should be named as ov_measID.nc. Considering the above example the sounding file should be named ov_20130101cc00.nc |
| 115 | 117 |
| 116 In this case you should also set the global attribute Overlap_File_Name in the raw lidar data file as: | 118 In this case you should also set the global attribute Overlap_File_Name in the raw lidar data file as:: |
| 117 | 119 |
| 118 Overalp_File_Name=ov_20130101cc00.nc | 120 Overlap_File_Name=ov_20130101cc00.nc |
| 121 | |
| 122 | |
| 123 Photocounting values should be integers | |
| 124 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| 125 Q: In one of my measurements I get an error concerning the photoncounting values:: | |
| 126 | |
| 127 Pre processing (177): Found no integer values in photoncounting signal | |
| 128 | |
| 129 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? | |
| 130 | |
| 131 A: Two important considerations: | |
| 132 | |
| 133 1. The Raw_Lidar_Data array should contain your *real* raw data. | |
| 134 This means that *no corrections/operations* should be made on your signals | |
| 135 before filling the Raw_Lidar_Data array. This is particularly important because *all* | |
| 136 the operations and corrections should be applied by the SCC and not by the user before | |
| 137 the submission. In this way we can keep track of all the operations made on the signals | |
| 138 (for QA purposes) and moreover we are sure that all the corrections are applied in a | |
| 139 correct order (this is particularly important for non linear operations, think for example to the dead time correction). | |
| 140 | |
| 141 2. The analog signals should be expressed in mV and the photoncounting signals in raw counts | |
| 142 | |
| 143 So if your photoncounting values are not integers they are not expressed in raw counts (which of course should be integers). | |
| 144 So the point here is not how to convert them in integers but to submit the right quantity in the right units. | |
| 145 | |
| 146 So please check carefully your converter and be sure to really submit raw counts for photoncounting channels and raw mV for the analog ones. | |
| 147 | |
| 148 | |
| 149 Preprocessing failed but no Exit code is provided | |
| 150 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
| 151 Q: The preprocessing of one of my measurements failed (I get a status -127). However, when I check the Exit codes | |
| 152 to see the description of the problem, I get an empty value (-). What does this mean? | |
| 153 | |
| 154 A: This means that the preprocessor crushed unexpectedly! Sorry for that! Report the problem in the forum and it will be fixed | |
| 155 soon. |
