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SeaDAS not Reading Data

Posted: Mon Mar 29, 2021 3:20 am America/New_York
by tedlenga
I am trying to load data into SeaDAS (Chlorophyll Concentration and SST) for the year 2019 but have not been successful from the month of August to December for CHL and for the entire year for SST.
However, I managed to read the data from January to July for 2019 CHL data. Kindly advise on what the issue could be.

Re: SeaDAS not Reading Data

Posted: Mon Mar 29, 2021 10:54 am America/New_York
by OB SeaDAS - xuanyang02
Please tell us what version of SeaDAS are you using? SeaDAS-7.5.3 or SeaDAS 8.0.0?
Are you trying to read L2 data?
I am able to read A2019256071000.L2_LAC_OC.nc (MODIS AQUA 2019-09-13) and AQUA_MODIS.20190913T071001.L2.SST.nc with both versions of SeaDAS.

Re: SeaDAS not Reading Data

Posted: Mon Mar 29, 2021 12:04 pm America/New_York
by tedlenga
I am using SeaDAS version 8.0.0 and trying to read L3 data.

Re: SeaDAS not Reading Data

Posted: Mon Mar 29, 2021 4:17 pm America/New_York
by gnwiii
tedlenga wrote:
> I am trying to load data into SeaDAS (Chlorophyll Concentration and SST)
> for the year 2019 but have not been successful from the month of August to
> December for CHL and for the entire year for SST.
> However, I managed to read the data from January to July for 2019 CHL data.
> Kindly advise on what the issue could be.

Are these files downloaded from the Ocean Color site? If so it would be helpful if you can provide the names and sizes of a couple of the files you can't load so it is easy to for others to test.

Re: SeaDAS not Reading Data

Posted: Tue Mar 30, 2021 12:02 pm America/New_York
by OB SeaDAS - xuanyang02
The L3b file format is not a raster image format. The internal data model for SeaDAS is based on 2D raster images, so visualizing the L3b files is not directly possible.
The data need to be mapped prior to display. You can use OCSSW -> l3mapgen to map L3b file to L3M file and read it.

Here is the link to the mapped data: https://oceandata.sci.gsfc.nasa.gov/MOD ... /sst/2019/

Re: SeaDAS not Reading Data

Posted: Wed Mar 31, 2021 3:09 am America/New_York
by tedlenga
gnwiii wrote:
> tedlenga wrote:
> > I am trying to load data into SeaDAS (Chlorophyll Concentration and SST)
> > for the year 2019 but have not been successful from the month of August to
> > December for CHL and for the entire year for SST.
> > However, I managed to read the data from January to July for 2019 CHL data.
> > Kindly advise on what the issue could be.
>
> Are these files downloaded from the Ocean Color site? If so it would be helpful if
> you can provide the names and sizes of a couple of the files you can't load so it is
> easy to for others to test.

The files have been downloaded from the OceanColor Web website. For instance, you can read file A20191212019151.L3m_MO_CHL_chlor_a_4km.nc which is for May 2019 but cannot read file A20192742019304.L3m_MO_CHL_chlor_a_4km.nc which is for October 2019 or AQUA_MODIS.20190101_20190131.L3m.MO.SST.sst.4km.nc which is SST for January 2019.

The sizes are around 50 MB.

Re: SeaDAS not Reading Data

Posted: Wed Mar 31, 2021 3:12 am America/New_York
by tedlenga
OB SeaDAS - xuanyang02 wrote:
> The L3b file format is not a raster image format. The internal data model for SeaDAS
> is based on 2D raster images, so visualizing the L3b files is not directly possible.
> The data need to be mapped prior to display. You can use OCSSW -> l3mapgen to map
> L3b file to L3M file and read it.
>
> Here is the link to the mapped data:
> https://oceandata.sci.gsfc.nasa.gov/MOD ... /sst/2019/

The files I am trying to read are in the L3m file format. For instance, you can read file A20191212019151.L3m_MO_CHL_chlor_a_4km.nc which is for May 2019 but cannot read file A20192742019304.L3m_MO_CHL_chlor_a_4km.nc which is for October 2019 or AQUA_MODIS.20190101_20190131.L3m.MO.SST.sst.4km.nc which is SST for January 2019.

Re: SeaDAS not Reading Data

Posted: Wed Mar 31, 2021 8:25 am America/New_York
by tedlenga
Below is the exception I am getting:

java.lang.NullPointerException
at gov.nasa.gsfc.seadas.dataio.SeadasFileReader.attributeToMetadata(SeadasFileReader.java:1242)
at gov.nasa.gsfc.seadas.dataio.SeadasFileReader.addAttributeToElement(SeadasFileReader.java:1227)
at gov.nasa.gsfc.seadas.dataio.SeadasFileReader.addAttributesToElement(SeadasFileReader.java:1221)
at gov.nasa.gsfc.seadas.dataio.SeadasFileReader.addGlobalMetadata(SeadasFileReader.java:873)
at gov.nasa.gsfc.seadas.dataio.SMIFileReader.createProduct(SMIFileReader.java:100)
at gov.nasa.gsfc.seadas.dataio.SeadasProductReader.readProductNodesImpl(SeadasProductReader.java:185)
at org.esa.snap.core.dataio.AbstractProductReader.readProductNodes(AbstractProductReader.java:178)
at org.esa.snap.core.dataio.ProductIO.readProduct(ProductIO.java:179)
at org.esa.snap.rcp.actions.file.ReadProductOperation.run(ReadProductOperation.java:61)
at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)

Re: SeaDAS not Reading Data

Posted: Wed Mar 31, 2021 4:23 pm America/New_York
by OB SeaDAS - xuanyang02
Thanks for sharing more detailed information. I did repeat your error reading A20192742019304.L3m_MO_CHL_chlor_a_4km.nc and AQUA_MODIS.20190101_20190131.L3m.MO.SST.sst.4km.nc.

It's a known issue for SeaDAS 8.0.0 in reading files with null value attributes in metadata. The fix will be in the next release.

In the meantime, you can read these L3 files with seadas-7.5.3. You can download it from here: https://oceandata.sci.gsfc.nasa.gov/Sea ... ler/7.5.3/

Re: SeaDAS not Reading Data

Posted: Thu Apr 01, 2021 3:13 am America/New_York
by tedlenga
Thanks for the clarification.