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RE: is there any OC processor for MODIS?
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Hello,

I am new to BEAM, used SeaDAS a lot. Is there a MODIS version of the C2R processor can be installed?

Best,
Yognzhen
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RE: is there any OC processor for MODIS?
3/28/17 5:30 PM as a reply to Yongzhen Fan.
Hi,
there is no MODIS version of C2R in BEAM.
Within SNAP, the successor of BEAM, there will be the C2RCC processor. Which is the successor of the C2R processor. This one will have a MODIS version.
It is not yet released, and therefor not yet documented, but if you are in a need then you can build it on your own and install it in SNAP.
How this can be done is explained in the readme

best wishes
Marco
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RE: is there any OC processor for MODIS?
3/28/17 7:33 PM as a reply to Marco Peters.
Dear Marco,

Thank you for the respond. i have installed SNAP and the C2RCC processors.

however, i would like to process a list of MODIS images. I figured out how to do this in BEAM with gpt, following your instruction here:
http://www.brockmann-consult.de/beam-wiki/display/BEAM/Bulk+Processing+with+GPT#BulkProcessingwithGPT-ExampleUsage

but these files does not work in SNAP, i think i need to change some of the command lines, but don't know how exactly. Can you show me an example how to use GPT in SNAP to process a list images?

BTW, i tried to use the graph builder in SNAP, but only c2rcc.lansat8 can be added, all the other c2rcc processors are not available.


Best,
Yongzhen
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RE: is there any OC processor for MODIS?
3/30/17 8:11 AM as a reply to Yongzhen Fan.
Which file do you mean which doesn't work? Probably the case2r.xml file. The batch scripts should still work after updating the path to gpt and changing the file filter (for /R %sourceDirectory% %%F in (*.N1) do ).
In order to get a new xml file for the c2rcc you can call on the command line
gpt <operator_name> -h
A list of the operator names is printed if you call
gpt -h
If you tell me more specifically what is not working I can help more specific.

The problem with the Graph Builder is that it doesn't support all GUIs and needs sometimes special GUI implementations. That's the reason why some are not shown here.
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RE: is there any OC processor for MODIS?
3/31/17 4:32 PM as a reply to Marco Peters.
Thank you Marco.
My question before was i don't know what operator name i should use. now that i know it should work, i will try to figure it out.

Another question, in c2rcc.modis algorithm, does rrs or Lw normalized (BRDF corrected)?
There is an option in MERIS algorithm to output normalized Lw, but no such option in the MODIS algorithm.

Best,
Yongzhen
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RE: is there any OC processor for MODIS?
4/3/17 11:53 AM as a reply to Yongzhen Fan.
For MODIS there is no normalisation performed.
There is only the option outputAsRrs (Output AC reflectances as rrs instead of rhow).
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RE: is there any OC processor for MODIS?
4/3/17 6:38 PM as a reply to Marco Peters.
Dear Marco,

Thank you for the information. I managed to wrote a script to do the bath processing. Thank you for the help.

The way i did it was to change the command line for every file such as:

gpt c2rcc.modis -t ./ZEBG/L2_C2RCC/A2014064121000_L2_C2RCC.nc -SsourceProduct=./ZEBG/L1C/A2014064121000.L1A_LAC.x.hdf.L1B.L1C -StomsomiStartProduct=./anc/2014/064/N201406400_O3_AURAOMI_24h.hdf -StomsomiEndProduct=./anc/2014/065/N201406500_O3_AURAOMI_24h.hdf -SncepStartProduct=./anc/2014/064/N201406412_MET_NCEPR2_6h.hdf -SncepEndProduct=./anc/2014/064/N201406418_MET_NCEPR2_6h.hdf -PoutputAsRrs=true -PoutputAngles=true -PoutputRtosa=true -Psalinity=35.0 -Ptemperature=15.0

however, i got some warning
WARNING: org.esa.s3tbx.dataio.modis.attribute.ImappAttributes: Unable to retrieve the product type from the file name.
WARNING: org.esa.snap.dataio.netcdf.util.MetadataUtils: Missing configuration property 'snap.dataio.netcdf.metadataElementLimit'. Using default (100).
WARNING: org.esa.s3tbx.dataio.modis.attribute.ImappAttributes: Unable to retrieve the product type from the file name.
WARNING: org.esa.snap.dataio.netcdf.util.MetadataUtils: Missing configuration property 'snap.dataio.netcdf.metadataElementLimit'. Using default (100).

did i miss anything in the package, perhaps some plugin that i did not install?

another question is where can i download the salinity and temperature file? the impact of temperature on rrs seems to be very small, less than 0.1% of difference in rrs between T=0.1 and T=30. But the salinity seems to have a larger impact on the rrs, there is difference up to 0.7% between salinity=30 and salinity=40.


Best,
Yongzhen
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RE: is there any OC processor for MODIS?
4/4/17 11:33 AM as a reply to Yongzhen Fan.
OK, Well done emoticon

you can ignore the log messages. Not very important.
The first is regarding the product type. No need to worry about. It seems that the tomsomi files are not in line with the expected file name convention of the generic reader.
The other one, regarding the missing property. This means that some metadata attributes might be cut off after 100 elements. But this will not interfere with you processing. you you like you can add this property to the snap.properties file in the etc directory of the installation folder and set it to 1000 or higher. There is already an issue for it.

For salinity and temperature you can check the Levitus dataset. Or the SST data which is available.
But probably you get better data from a local provider.
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RE: is there any OC processor for MODIS?
4/7/17 6:25 PM as a reply to Marco Peters.
Thank you Marco, it's good to know that the warning messages are not a problem.

I am currently preparing an revised version of a manuscript that compares several AC algorithms (SeaDAS NIR, NIR-SWIR, and OC-SMART) in coastal regions. the reviewer suggested that we include the NN algorithm for MERIS, that's why i am processing all the data using c2rcc algorithm.The authors of the manuscript include Cedric Jamet, Giuseppe Zibordi,Thomas Schroeder, Charles K. Gatebe, Knut Stamnes, Wei Li and myself. But before I put in any of the results in the manuscript, i would like to know what is the protocol for using the images processed by the C2RCC algorithm? Citation and acknowledgement will be certainly added, is there any other requirements for using the images?

Best,
Yongzhen
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RE: is there any OC processor for MODIS?
4/10/17 10:05 AM as a reply to Yongzhen Fan.
Hi Yongzhen,
citation und acknowledgement is sufficient. There are no other requirements.

The results of the comparison are very interesting.
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RE: is there any OC processor for MODIS?
9/4/17 6:06 PM as a reply to Marco Peters.
Hi Marco,
C2RCC MODIS processor expects a l1c product as input.
Where can I can this data, or how can I process it?
I can manually process from L0 to L1a or b in Seadas, but i cant find anything for l1c.
Thanks for any help.
B.
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RE: is there any OC processor for MODIS?
9/5/17 1:43 PM as a reply to bennet juhls.
Hi,

The L1C files can be generated with l2gen.
You will need the geolocation file for you MODIS product.

A sample call to l2gen can look like:
1l2gen ifile=<inputFilePath> geofile=<gelocationFilePath> ofile=<outputFilePath>.L1C.nc gain=1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0 l2prod="rhot_nnn polcor_nnn sena senz sola solz latitude longitude"


Actually, you can name the output file as you like, But we use the '.L1C.nc' suffix

L1C is kind of an ESA invention. It was defined in the frame of the OC-CCI project. The C2RCC needs those products as input too.

I'm attaching also a screenshot of the L2Gen GUI.
Attachment

Attachments: L2gen_GUI.png (127.8k)
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