sentinel 3 band names to use in gpt

[fbecker23]

Hello,
I am new to using Sentinel 3 imagery, but I have been using gpt to process VIIRS L2 imagery. I want to modify my .xml to OLCI images from Sentinel 3, but I don't know how I should name the different bands or reflectances. In the .xml I also do a reprojection and change the format to NetCDF4-CF.
As an example I leave one of the images that I intend to use "S3A_OL_2_WFR____20231114T132138_20231114T132438_20231114T151644_0180_105_309_3600_MAR_O_NR_003.SEN3"
Here is an example of what I would like to use in the .xml.

#######
<graph id="firstGraph">
<version>1.0</version>

<node id="Read_chl">
<operator>Read</operator>
<sources/>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<file>${filechl}</file>
</parameters>
</node>

<node id="BandMaths_chl">
<operator>BandMaths</operator>
<sources>
<sourceProduct refid="Read_chl"/>
</sources>
<parameters>
<targetBands>
<!-- Chlorofill-a NN band name-->
<targetBand>
<name>chl</name>
<expression>CHL_NN</expression>
<description></description>
<type>float32</type>
<noDataValue>NaN</noDataValue>
</targetBand>
<!-- Reflectance band name-->
<targetBand>
<name>400nm_reflectance</name>
<expression>Oa01_reflectance</expression>
<description></description>
<type>int32</type>
<noDataValue>NaN</noDataValue>
</targetBand>
<targetBand>
<name>560_reflectance</name>
<expression>Oa01_reflectance</expression>
<description></description>
<type>int32</type>
<noDataValue>NaN</noDataValue>
</targetBand>
<!-- Mask band name-->
<targetBand>
<name>LAND</name>
<expression>WQSF_lsbLAND</expression>
<description></description>
<type>int32</type>
<noDataValue>NaN</noDataValue>
</targetBand>
<node id="Write">
<operator>Write</operator>
<sources>
<source>BandMaths_chl</source>
</sources>
<parameters>
<file>${ofile}</file>
<formatName>NetCDF4-CF</formatName>
</parameters>
</node>

</graph>
#######

I want to know how to reference the variable chl, the different reflectances and masks. I try to see this in the handbook of https://nikal.eventsair.com/QuickEventWebsitePortal/sentinel-3-validation-team-s3vt/esa/ExtraContent/ContentPage?page=2 , but the page is down.

Regards
Fernando

[OB SeaDAS - xuanyang02]

If you use L2 files from our site, you should be able to use gpt as you do with VIIRS L2 files. - https://oceandata.sci.gsfc.nasa.gov/directdataaccess/Level-2/S3A-OLCI/2023/318/

If you choose to use the file from ESA, for the band CHL_NN, your filechl is S3A_OL_2_WFR____20231114T132138_20231114T132438_20231116T015819_0180_105_309_3600_MAR_O_NT_003.SEN3/S3A_OL_2_WFR____20231114T132138_20231114T132438_20231116T015819_0180_105_309_3600_MAR_O_NT_003.SEN3/chl_nn.nc, and your band is CHL_NN. You can't have Oa01_reflectance in the same xml file, because Oa01_reflectance is in the file Oa01_reflectance.nc, not chl_nn.nc

[fbecker23]

Thank you xuanyang02!