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[python #RHP-234890]: Questions About GOES Imagery



Greetings!

Apologies for the delayed response. Regarding the times, here's the meaning of 
the times beginning with s, e, and c:

- s: start of collection
- e: end of collection
- c: file creation time

On the issue of saving datasets locally, I'm having no trouble with a slightly 
modified version of your code:

from siphon.catalog import TDSCatalog
from pathlib import Path
import xarray as xr

catalog = 
TDSCatalog('https://thredds.ucar.edu/thredds/catalog/satellite/goes/east/products/CloudAndMoistureImagery/CONUS/Channel03/current/catalog.xml')

ds = catalog.datasets[0]
local_file = ds.name
ds.download(local_file)

ds = xr.open_dataset(local_file, engine='netcdf4')

which saves the file in the same directory as the script, so I'm wondering if 
it's either an issue with downloading the data on your system, or perhaps a 
path issue. Can you try going to: 

  
https://thredds.ucar.edu/thredds/fileServer/satellite/goes/east/products/CloudAndMoistureImagery/CONUS/Channel03/current/OR_ABI-L2-CMIPC-M6C03_G16_s20230852046160_e20230852046160_c20230852046160.nc

To download the file directly, and see if you can open that with xarray?

Cheers,

Ryan

> Hi,
> 
> sorry for the repeated emails. I feel a little stupid, as I realized the 
> timestamps are just YYYYDDDHHMMSSs where Y is the year, D is the day number 
> of the year, H is the hour, M is the minute & S is the second, with s 
> apparently being tenths of a second.
> 
> Further questions:
> 
> *   I assume these are UTC times?
> *   What do the times represent?
> 
> Beyond that, I'm still wondering about the issues with saving/loading 
> datasets locally, which I have not gotten to work.
> 
> 
> Hello,
> 
> I did a little more investigating about the GOES dataset naming conventions. 
> As far as I can tell, the numbers are indeed timestamps, counting from the 
> start of the current year. The first 4 digits are the year, the next 3 digits 
> are the day of year, and the final 7 digits are time of day given in units of 
> ten-millionths of a day (i.e. they increment by 1 for every 8.64 ms such that 
> they change by 1e7 for every day). Can you confirm I have it right?
> 
> What's the meaning of s?, e? and c?, then? And how about OR? and M6C03??
> 
> Also, about the data formats. I see in the metadata that the files are 
> advertised to be in NetCDF-4 format. Any idea why I am having trouble 
> saving/loading them, then?
> 
> Thanks in advance,


Ticket Details
===================
Ticket ID: RHP-234890
Department: Support Python
Priority: Low
Status: Closed
===================
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