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NOAA CLASS files

Posted: Wed Mar 27, 2024 11:24 am
by Cloudy
I downloaded the following files from NOAA CLASS:
OR_ABI-L1b-RadF-M6C02_G16_s20233612100203_e20233612109511_c20233612109549.nc
and
OR_ABI-L1b-RadF-M6C02_G16_s20233612100203_e20233612109511_c20233612109549.nc.meta
I can't open them in McIDAS-V Version: 1.9beta1 Build-date: 2023-03-14 03:00.
Previously I downloaded files in area format, but now they come out with .nc.
How can I open them in McIDAS-V? Thank you

Re: NOAA CLASS files

Posted: Wed Mar 27, 2024 12:16 pm
by bobc
Hello,

Dependent on your operating system, there are a couple ways you can work with the netCDF (*.nc) file in McIDAS-V:
  1. If you are on Linux or macOS, you can create a local dataset through the ADDE Data Manager (Tools>Manage ADDE Datasets) with the GOES ABI format. You can then access this local dataset through the Satellite>Imagery chooser of the Data Explorer.
  2. On any platform, including Windows, you can load the netCDF file as a gridded data source through the General>Files/Directories chooser of the Data Explorer using the "Grid files (netCDF/GRIB/OPeNDAP/GEMPAK)" data type. This will give you access to the radiance and quality flag variables.
I'm not familiar with the "nc.meta" format. I'm assuming you got this by selecting "Both netCDF and NCML" in the Advanced options when ordering?
NOAA CLASS ordering options
NOAA CLASS ordering options
class.png (9.37 KiB) Viewed 14073 times
I tried ordering the data with this option to verify, but CLASS just went down for maintenance. Is this where you previously saw AREA as a valid format to order? I don't recall ever downloading AREA format data from CLASS in the past, only netCDF format for ABI data.

If you would like me to verify if your data files work or not, you can put them on our ftp:

ftp ftp.ssec.wisc.edu
user: anonymous
password: email
bin
prom
cd pub/incoming
put OR_ABI-L1b-RadF-M6C02_G16_s20233612100203_e20233612109511_c20233612109549.nc
put OR_ABI-L1b-RadF-M6C02_G16_s20233612100203_e20233612109511_c20233612109549.nc.meta
bye

Please let me know if you post the files to ftp and I will grab them to try. Also, I wanted to mention that McIDAS-V 1.9 was released last November and is available on the Downloads page.

Thanks,
Bob Carp
McIDAS User Services

Re: NOAA CLASS files

Posted: Fri Apr 05, 2024 4:18 pm
by Cloudy
I was able to load the *.nc files downloaded from CLASS, thanks for the help. But now I have a new problem, if I load several nc files in McIDAS-V it displays only one. Any suggestion?

Re: NOAA CLASS files

Posted: Fri Apr 05, 2024 5:29 pm
by bobc
Hello,

I'm assuming you are loading the data through the General>Files/Directories chooser. By default, this loads the data as a single-time gridded data source. There's a data type "Aggregate Grids by Time" that would allow you to select multiple files, click Add Source, and then be able to display a loop from the Field Selector. This works for all gridded netCDF/grib/hdf files that have a "time" dimension. These ABI netCDF files don't have this time dimension, so attempting to aggregate the data this way does not work.

If you want to create a loop of multiple ABI netCDF files, you will have to utilize NcML to extract the date/time information from the filenames. There are other forum posts where this is described in more detail, such as here. You can find more general information about NcML aggregation here. An NcML file you can try is attached to this post. To load the data, put the NcML file in the same directory as your ABI netCDF data and load the NcML file as a gridded data source through the General>Files/Directories chooser.

Please let me know if you have any further questions on this topic.

Thanks,
Bob

Re: NOAA CLASS files

Posted: Sat Apr 06, 2024 1:40 am
by Cloudy
Hi Bob, following your instructions I was able to upload multiple *.nc files with NCML. In the directory with the netcdf data I added the aggregation.ncml file and I was able to upload multiple files. Many thanks for all