| 1 Frequently asked questions |
1 Frequently asked questions |
| 2 ========================== |
2 ========================== |
| 3 |
3 |
| 4 Is it necessary to provide only measurment periods with cloud free conditions and |
4 Clouds in the data |
| 5 homogeneous atmosphere or is this part of ELDA or the pre processing of the data? |
5 ~~~~~~~~~~~~~~~~~~ |
| 6 For example in cases with scattered low cumulus clouds. |
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| 7 |
6 |
| 8 At moment you should provide cloud free data because the automatic cloud screening |
7 Q: Is it necessary to provide only measurment periods with cloud free conditions and |
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8 homogeneous atmosphere or is this part of ELDA or the pre processing of the data? |
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9 For example in cases with scattered low cumulus clouds. |
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10 |
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11 A: At moment you should provide cloud free data because the automatic cloud screening |
| 9 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 |
| 10 module will be implemented at the end of ACTRIS project . |
13 module will be implemented at the end of ACTRIS project . |
| 11 |
14 |
| 12 What is the definition of low range, ultra near range and high range channels? |
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| 13 Are there any threshold values? |
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| 14 |
15 |
| 15 There are no threshold values defined for the different range types. This information |
16 High/low range channels |
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17 ~~~~~~~~~~~~~~~~~~~~~~~ |
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18 Q: What is the definition of low range, ultra near range and high range channels? |
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19 Are there any threshold values? |
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20 |
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21 A: There are no threshold values defined for the different range types. This information |
| 16 is used only in the gluing procedures just to identify which channel should be taken |
22 is used only in the gluing procedures just to identify which channel should be taken |
| 17 as low range and which one as far range. If no gluing is applied by the SCC the range |
23 as low range and which one as far range. If no gluing is applied by the SCC the range |
| 18 id flags are not taken into account. |
24 id flags are not taken into account. |
| 19 |
25 |
| 20 Due to changes in the settings of our lidarsystem, the depolarization factor can |
26 Variable depolarization factor |
| 21 change during the measurement. Is it necessary to provide one SCC-file for each settings |
27 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 22 or is it possible to set the Depolarization_Factor variable time dependent? |
28 |
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29 Q: Due to changes in the settings of our lidarsystem, the depolarization factor can |
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30 change during the measurement. Is it necessary to provide one SCC-file for each settings |
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31 or is it possible to set the Depolarization_Factor variable time dependent? |
| 23 |
32 |
| 24 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. |
| 25 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. |
| 26 |
35 |
| 27 Is it possible for documentation purposes to put own parameters in the SCC-NetCDF file? |
36 Extra netcdf parameters |
| 28 For example who created the file.... Are there any reasons against this? |
37 ~~~~~~~~~~~~~~~~~~~~~~~ |
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38 Q: Is it possible for documentation purposes to put own parameters in the SCC-NetCDF file? |
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39 For example who created the file.... Are there any reasons against this? |
| 29 |
40 |
| 30 Technically as long as you use not standard SCC variables for your own parameters there are |
41 A: Technically as long as you use not standard SCC variables for your own parameters there are |
| 31 no problems for the SCC. It will just ignore these not standard variables. |
42 no problems for the SCC. It will just ignore these not standard variables. |
| 32 |
43 |
| 33 Which NetCDF version is to use? NetCDF3, NetCDF3 Classic, NetCDF4, NetCDF4 Classic? |
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| 34 |
44 |
| 35 The NetCDF libraries 4.1.3 are used in all the SCC modules. So all the NetCDF formats you |
45 Netcdf version |
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46 ~~~~~~~~~~~~~~ |
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47 Q: Which NetCDF version is to use? NetCDF3, NetCDF3 Classic, NetCDF4, NetCDF4 Classic? |
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48 |
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49 A: The NetCDF libraries 4.1.3 are used in all the SCC modules. So all the NetCDF formats you |
| 36 have indicated should be compatible with the SCC (we have tested NetCDF3 and NetCDF4). |
50 have indicated should be compatible with the SCC (we have tested NetCDF3 and NetCDF4). |
| 37 |
51 |
| 38 What are the values for the lidar ratio used in the SCC_DB? |
52 Lidar ratio |
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53 ~~~~~~~~~~~ |
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54 Q: What are the values for the lidar ratio used in the SCC_DB? |
| 39 |
55 |
| 40 The values of (fixed) lidar ratio used by the SCC in the elastic retrieval can be set by |
56 A: The values of (fixed) lidar ratio used by the SCC in the elastic retrieval can be set by |
| 41 the user using the SCC web interface. In particular you can define a lidar ratio value for |
57 the user using the SCC web interface. In particular you can define a lidar ratio value for |
| 42 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 |
| 43 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 |
| 44 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 |
| 45 (see documentation on SCC file format). |
61 (see documentation on SCC file format). |
| 46 |
62 |
| 47 In cases of measurements where Raman channels are available, the SCC will calculate the Raman |
63 Calculation of raman and elastic backsatter |
| 48 backscatter profile. If I want to retrieve Klett-retrievals for this channel, too (e.g 532nm) |
64 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 49 is it sufficient to set the value in LR_input(channels) to 1 or 0 plus a LR-profile to get |
65 Q: In cases of measurements where Raman channels are available, the SCC will calculate the Raman |
| 50 both retrievals? |
66 backscatter profile. If I want to retrieve Klett-retrievals for this channel, too (e.g 532nm) |
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67 is it sufficient to set the value in LR_input(channels) to 1 or 0 plus a LR-profile to get |
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68 both retrievals? |
| 51 |
69 |
| 52 No. In general, for each lidar configuration you can define a set of optical products to be calculated |
70 A: No. In general, for each lidar configuration you can define a set of optical products to be calculated |
| 53 for that configuration using the SCC web interface. So suppose you have a system with 532nm and 607nm |
71 for that configuration using the SCC web interface. So suppose you have a system with 532nm and 607nm |
| 54 channels. In this case you have 2 options: |
72 channels. In this case you have 2 options: |
| 55 #. Raman backscatter and extinction in the e532 file and Raman backscatter (full resolution) in the b532 |
73 |
| 56 file. In this case you should associate to the configuration a product of type “lidar ratio and will |
74 1. Raman backscatter and extinction in the e532 file and Raman backscatter (full resolution) in the b532 |
| 57 produce the e532 file and a product of type “Raman backscatter” which will produce the b532 file |
75 file. In this case you should associate to the configuration a product of type "lidar ratio and will |
| 58 #. Raman backscatter and extinction in the e532 file and elastic backscatter in the b532 file. |
76 produce the e532 file and a product of type "Raman backscatter" which will produce the b532 file |
| 59 In this case you should associate to the configuration a product of type “lidar ratio and extinction” |
77 2. Raman backscatter and extinction in the e532 file and elastic backscatter in the b532 file. |
| 60 which will produce the e532 file and a product of type “elastic backscatter” which will produce the b532 file |
78 In this case you should associate to the configuration a product of type "lidar ratio and extinction" |
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79 which will produce the e532 file and a product of type "elastic backscatter" which will produce the b532 file |
| 61 |
80 |
| 62 Note: you cannot calculate a b532 file containing the Raman and elastic backscatters at the same time. |
81 Note: you cannot calculate a b532 file containing the Raman and elastic backscatters at the same time. |
| 63 The reason is that the 2 products will produce an output file with the same name (according to the EARLINET rules). |
82 The reason is that the 2 products will produce an output file with the same name (according to the EARLINET rules). |
| 64 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 |
| 65 one which usually is better. |
84 one which usually is better. |
| 66 |
85 |
| 67 What are the conventions for the filnames for the various files that need to be uploaded? |
86 Filename conventions |
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87 ~~~~~~~~~~~~~~~~~~~~ |
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88 A: What are the conventions for the filnames for the various files that need to be uploaded? |
| 68 |
89 |
| 69 The following definitions apply: |
90 Q: The following definitions apply: |
| 70 - SCC raw lidar data file |
91 - SCC raw lidar data file |
| 71 |
92 |
| 72 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 |
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 |
| 73 |
94 |
| 74 - Sounding file |
95 Sounding file |
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96 ^^^^^^^^^^^^^ |
| 75 |
97 |
| 76 The file should be named as rs_measID.nc. Considering the above example the sounding file should be named rs_20130101cc00.nc |
98 The file should be named as rs_measID.nc. Considering the above example the sounding file should be named rs_20130101cc00.nc |
| 77 |
99 |
| 78 In this case you should also set the global attribute Sounding_File_Name in the raw lidar data file as: |
100 In this case you should also set the global attribute Sounding_File_Name in the raw lidar data file as: |
| 79 |
101 |
| 80 Sounding_File_Name=rs_20130101cc00.nc |
102 Sounding_File_Name=rs_20130101cc00.nc |
| 81 |
103 |
| 82 - Lidarration file |
104 Lidar ratio file |
| 83 |
105 ^^^^^^^^^^^^^^^^ |
| 84 The file should be named as lr_measID.nc. Considering the above example the sounding file should be named lr_20130101cc00.nc |
106 The file should be named as lr_measID.nc. Considering the above example the sounding file should be named lr_20130101cc00.nc |
| 85 |
107 |
| 86 In this case you should also set the global attribute LR_File_Name in the raw lidar data file as: |
108 In this case you should also set the global attribute LR_File_Name in the raw lidar data file as: |
| 87 |
109 |
| 88 LR_File_Name=lr_20130101cc00.nc |
110 LR_File_Name=lr_20130101cc00.nc |
| 89 |
111 |
| 90 - Overlap file |
112 Overlap file |
| 91 |
113 ^^^^^^^^^^^^ |
| 92 The file should be named as ov_measID.nc. Considering the above example the sounding file should be named ov_20130101cc00.nc |
114 The file should be named as ov_measID.nc. Considering the above example the sounding file should be named ov_20130101cc00.nc |
| 93 |
115 |
| 94 In this case you should also set the global attribute Overlap_File_Name in the raw lidar data file as: |
116 In this case you should also set the global attribute Overlap_File_Name in the raw lidar data file as: |
| 95 |
117 |
| 96 Overalp_File_Name=ov_20130101cc00.nc |
118 Overalp_File_Name=ov_20130101cc00.nc |
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| 98 |
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| 99 |
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| 100 |
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