modis_atteph.py is downloading the wrong ATT/EPH pair

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user_gis
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Joined: Thu Jul 28, 2016 11:19 am America/New_York

Re: modis_atteph.py is downloading the wrong ATT/EPH pair

by user_gis » Fri May 27, 2022 12:45 am America/New_York

If it's possible, let me know about the completion of work with the new API.
Thanks...

Regards,
Dmitry

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OB SeaDAS - xuanyang02
Subject Matter Expert
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Re: modis_atteph.py is downloading the wrong ATT/EPH pair

by OB SeaDAS - xuanyang02 » Fri May 27, 2022 2:32 pm America/New_York

Sure, we will notify you once the new API and script work as expected.

Meanwhile, you can still use the V2021.2 or earlier OCSSW

user_gis
Posts: 21
Joined: Thu Jul 28, 2016 11:19 am America/New_York

Re: modis_atteph.py is downloading the wrong ATT/EPH pair

by user_gis » Mon May 30, 2022 6:15 am America/New_York

Thanks,

I don't know your plans to update the API, but it would be nice if the new API could check MODIS data coverage with att/eph data before generating a GEO file using a given threshold, rather than just perform a data coverage check on their relevance to use.

What I mean:

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Aqua

Input file: A2022149111601.L1A_LAC
Sensor    : aqua
Start time: 2022149111601
End time  : 2022149112500

OBPG session started
Downloading A2022149111601.anc.server (    0.00 MBs)
[==================================================]
...Done
  Found: /opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1110.061
  Found: /opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1115.061
  Found: /opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1120.061
  Found: /opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1125.061
  Found: /opt/rki/ocssw/var/anc/2022/148/PM1EPHND.P2022148.1200.003
All required attitude and ephemeris files successfully determined and downloaded.
att1=/opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1110.061
att2=/opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1115.061
att3=/opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1120.061
att4=/opt/rki/ocssw/var/anc/2022/149/PM1ATTNR_NRT.A2022149.1125.061
eph1=/opt/rki/ocssw/var/anc/2022/148/PM1EPHND.P2022148.1200.003

- All optimal ancillary data files were determined and downloaded. -

Code: Select all

echo $?
1

Then I create a GEO file and do modis_geocheck.

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modis_GEO --enable-dem A2022149111601.L1A_LAC

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modis_geocheck --verbose --threshold 100 A2022149111601.GEO
Percentage of pixels with missing geolocation:
0.00

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Validation test passed for geolocation file A2022149111601.GEO
It turns out that output status 1 has nothing to do with the actual ATT/EPH data coverage.

Thanks, again.

Regards,
Dmitry

OB SeaDAS - xuanyang02
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Re: modis_atteph.py is downloading the wrong ATT/EPH pair

by OB SeaDAS - xuanyang02 » Tue May 31, 2022 3:40 pm America/New_York

True, modis_atteph.py does not have knowledge of failed pixel geolocation. It looks at the L1 file to determine the scene start and stop time which it then uses to select and download the correct ancillary data.

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