Earthdata Forum

Hello,
We are using Seadas 7.3 , and in the last day or so, we have started running into errors with modis_GEO.py retrieving ancillary files.
Did something change with in how these files are supposed to be retrieved?

Here is the error we are seeing:


modis_GEO.py -v --threshold\=80\ T2017355213158.L1A_LAC

Determining required attitude and ephemeris files...

Searching database: /opt/modis/ocssw/run/var/ancillary_data.db

Input file: T2017355213158.L1A_LAC

Start time: 2017355213158

End time: 2017355214129

Connection interrupted, retrying up to 5 more time(s)

Connection interrupted, retrying up to 4 more time(s)

Connection interrupted, retrying up to 3 more time(s)

Connection interrupted, retrying up to 2 more time(s)

Connection interrupted, retrying up to 1 more time(s)

We failed to reach a server.

Please retry this request at a later time.

URL attempted: oceancolor.gsfc.nasa.gov

HTTP Error: 410 - Gone

Error retrieving ancillary file list

Cannot create geolocation from T2017355213158.L1A_LAC; exiting.



SeaDAS 7.3 stopped working for us a year ago when NASA made the switch to https, which is supported in 7.4.   Did you update your OCSSW Processing system? 
To check:

$ cd $OCSSWROOT/run/scripts/
$ git status
On branch v7.4
Your branch is up to date with 'origin/v7.4'.

nothing to commit, working tree clean

In the past week I've encountered problems with a number of https URL's that have worked in the recent past.   I assume the have been updates to our firewalls, as some of the problem sites fail on multiple systems at work but not from home.    To rule out changes between you and NASA, you can try downloading files with a browser from the NASA ocean data server.  I grabbed the smallest file for day 355 and get:

$ modis_GEO.py -v T2017355213000.L1A_LAC
Determining required attitude and ephemeris files...
Searching database: /Users/seadas/ocssw/run/var/ancillary_data.db

Input file: T2017355213000.L1A_LAC
Start time: 2017355213000
End time: 2017355213459

Downloading 'AM1EPHN0.A2017355.2000.002' to /Users/seadas/ocssw/run/var/anc/2017/355
Downloading 'AM1ATTN0.A2017355.2000.002' to /Users/seadas/ocssw/run/var/anc/2017/355

Creating MODIS geolocation file...
GEO version: 6.0.11 built on Apr 27 2016 (10:21:59)
scan: 0 out of 203 Fri Dec 22 08:02:44 2017
[...]
scan: 200 out of 203 Fri Dec 22 08:02:52 2017
geogen_modis returned with exit status: 0
Percentage of pixels with missing geolocation: 0.00
Validation test passed for geolocation file T2017355213000.GEO
geogen_modis created T2017355213000.GEO successfully!
MODIS geolocation processing complete.

Can you download AM1EPHN0.A2017355.2000.002 with a browser, wget, curl, etc?  If so, your OCSSW processing software might be using the old http URL's , or your python SSL library might not support the ciphers required by NASA https servers.  A number of posts from a year ago show how to check the python SSL library.

The machine running the backend service for getanc.py for v7.3 is no longer happy doing so.   You can either upgrade your complete SeaDAS install to v7.4 or just the scripts directory.
To do just the scripts, when in the $OCSSWROOT/run/scripts directory, run git pull followed by git checkout v7.4

Sean