Terra MODIS L1 failures

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sdasgupta
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Joined: Wed Jun 29, 2022 10:05 am America/New_York

Terra MODIS L1 failures

by sdasgupta » Wed Jun 29, 2022 10:09 am America/New_York

Terra MODIS Level 0 to Level1 processing started to fail for GSFC Direct Broadcast passes starting 6/27/2022. Similar failures have also been reported by other Direct Broadcast stations. FYI, our (Direct Readout lab's) modisl1db package represents Seadas-ocssw, direct broadcast bundle V2021.2 tag and the package was created with guidance from OBPG.
The error messages were as follows
“ERROR: display_ancillary_files.cgi script returned blank entry for att0. Exiting.
Failed to identify/retrieve attitude/ephemeris required to geolocate MOD01.22179023847.hdf; exiting.”
We suspect that the anc_utils.py script under the seadasutils module is failing to query/fetch the attitude and ephemeris ancillary files. Can you provide guidance on how to address these failures?

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OB SeaDAS - xuanyang02
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Answers: 1

Re: Terra MODIS L1 failures

by OB SeaDAS - xuanyang02 » Wed Jun 29, 2022 12:07 pm America/New_York

Yes, anc_utils.py script is failing to get the attitude and ephemeris ancillary files because they are not available. It seems that the average latency for terra att/eph has increased about 100 minutes from 7-10 hours to 9-11 hours since mid June.

See viewtopic.php?p=11642#p11619

Bing

sdasgupta
Posts: 2
Joined: Wed Jun 29, 2022 10:05 am America/New_York

Re: Terra MODIS L1 failures

by sdasgupta » Tue Jul 05, 2022 11:25 am America/New_York

Thanks for your response. Looks like the problem hasn't been resolved yet. Real time Terra processing at Direct Broadcast sites continue to fail due to this ancillary latency issue. When is this issue expected to be resolved ? Thanks.

jay_cable
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Joined: Wed Feb 01, 2017 4:22 pm America/New_York

Re: Terra MODIS L1 failures

by jay_cable » Wed Jul 06, 2022 3:48 pm America/New_York

Is there any update to this? Thanks!

OB SeaDAS - xuanyang02
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Re: Terra MODIS L1 failures

by OB SeaDAS - xuanyang02 » Wed Jul 06, 2022 4:18 pm America/New_York

We have no control over this ancillary latency issue, it's upstream from us. However, the issue seems to improve.

It's 20:16:00 UTC right now, and I am able to do modis_atteph and modis_GEO on T2022187135000.L1A_LAC

$ modis_atteph T2022187135000.L1A_LAC
Running debug binaries...
/Users/*/ocssw/bin
Terra
ancillary_data.db
Terra
att1=/Users/*/ocssw/var/anc/2022/187/AM1ATTN0.A2022187.1200.002
eph1=/Users/*/ocssw/var/anc/2022/187/AM1EPHN0.A2022187.1200.002

$ modis_GEO T2022187135000.L1A_LAC
Running debug binaries...
/Users/*/ocssw/bin
Running debug binaries...
/Users/*/ocssw/bin
ancillary_data.db
MODIS GEO version 6.1.0, built Jan 11 2022 14:31:07
scan: 0 out of 203 Wed Jul 6 16:14:50 2022
scan: 10 out of 203 Wed Jul 6 16:14:51 2022
scan: 20 out of 203 Wed Jul 6 16:14:51 2022
scan: 30 out of 203 Wed Jul 6 16:14:52 2022
scan: 40 out of 203 Wed Jul 6 16:14:52 2022
scan: 50 out of 203 Wed Jul 6 16:14:52 2022
scan: 60 out of 203 Wed Jul 6 16:14:53 2022
scan: 70 out of 203 Wed Jul 6 16:14:53 2022
scan: 80 out of 203 Wed Jul 6 16:14:53 2022
scan: 90 out of 203 Wed Jul 6 16:14:54 2022
scan: 100 out of 203 Wed Jul 6 16:14:54 2022
scan: 110 out of 203 Wed Jul 6 16:14:54 2022
scan: 120 out of 203 Wed Jul 6 16:14:55 2022
scan: 130 out of 203 Wed Jul 6 16:14:55 2022
scan: 140 out of 203 Wed Jul 6 16:14:55 2022
scan: 150 out of 203 Wed Jul 6 16:14:56 2022
scan: 160 out of 203 Wed Jul 6 16:14:56 2022
scan: 170 out of 203 Wed Jul 6 16:14:56 2022
scan: 180 out of 203 Wed Jul 6 16:14:57 2022
scan: 190 out of 203 Wed Jul 6 16:14:57 2022
scan: 200 out of 203 Wed Jul 6 16:14:57 2022

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