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Posted: Thu Dec 09, 2021 9:42 am America/New_York
by mchl.mccrthy
Hi all,

I'm using Python to download some MODIS data through the AppEEARS API. In my task request, I submit a tupled list of the layer and product I want to download, in this case: NDSI_Snow_Cover, MOD10A1.006. Everything works fine, except that as well as the NDSI_Snow_Cover layer, I also get the NDSI_Snow_Cover_Algorithm_Flags_QA and NDSI_Snow_Cover_Basic_QA layers. I'm guessing this happens because these layer names also contain 'NDSI_Snow_Cover', because I don't get e.g. the orbit_pnt or Snow_Albedo_Daily_Tile layers that are also associated with MOD10A1.006. I don't need the QA layers, and they take a long time to process and download, so I'd rather not get them if possible.

Any ideas as to how to solve this issue?

Thanks a lot!


Posted: Thu Jan 20, 2022 12:19 pm America/New_York
by LP DAAC - jwilson
We apologize for the delayed response. We have sent this to our Subject Matter Expert for further guidance.


Posted: Thu Jan 20, 2022 3:16 pm America/New_York
by LP DAAC - afriesz
@mchl.mccrthy ,

We strongly encourage anyone working with data from any NASA DAAC to consult the associated quality data layers or metadata. The automatic return of associated quality data is a foundational component of the AppEEARS system and is something we cannot turn off. However, data files produced by AppEEARS can be downloaded individually from either the web application or from the AppEEARS API. If you’re using the tutorial Getting Started with the AρρEEARS API: Submitting and Downloading an Area Request, you can filter the files bundle to only download the file you want. To exclude any QA files from your download, you could try the following on the ‘files’ object in section 4b cell 34 of the tutorial:

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files_noQC = {f:files[f] for f in files.keys() if 'QC' not in files[f]}
There are probably better ways to do this, but the line of code will return all files except files with ‘QC’ in their name. You could also add a bit more to only include only ‘.tif’ files without ‘QC’ in their name:

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files_noQC_tif = {f:files[f] for f in files.keys() if 'QC' not in files[f] and '.tif' in files[f]}
I hope this helps.


Posted: Mon May 09, 2022 11:00 am America/New_York
by mchl.mccrthy
Thanks very much @afriesz, this is helpful and I completely agree the QC is important. Here I wanted a rough estimate relatively quickly, and I suppose I was surprised I couldn't choose. I agree though, this functionality makes sense. All the best