MODIS GEO file

[avmehta]

Hello,
    I am using modis_GEO.py  with L1A MODIS file to get a GEO file. For many files I get the following error:

     Percent valid data (0.00) is less than threshold (95.00)
     ERROR: MODIS geolocation processing failed.

   I am trying to find out how 'valid data' are defined.

Thank you.
Amita

[OB.DAACx - SeanBailey]

Amita,

When the MODIS geolocation processing fails, it leaves behind several log files (with filenames that begin with "Log").  These can be cryptic, but are informative.
If you can't decipher them, and don't see a similar post on this forum explaining the issue, attach the log files (or snippets that seem interesting) and someone may be able to help you.

Sean

[maheshgeotech38]

Dear sir,
                Please guide how to solve the solution this error

I am try to generate L1B data from L1A data of MODIS aqua, followed by command ::::: modis_GEO.py filename

Traceback (most recent call last):
  File "/home/umamahesh/ocssw/scripts/modis_GEO.py", line 7, in <module>
    import modules.anc_utils as anc_utils
  File "/home/umamahesh/ocssw/scripts/modules/anc_utils.py", line 9, in <module>
    import modules.ProcUtils as ProcUtils
  File "/home/umamahesh/ocssw/scripts/modules/ProcUtils.py", line 16, in <module>
    import requests
ImportError: No module named requests

[maheshgeotech38]

Dear Sir,

             Good morning, when running the command: modis_GEO.py filename

*** ERROR: Authentication Failue retrieving:
*** oceandata.sci.gsfc.nasa.gov/ob/getfile/PM1ATTNR.P2012062.0600.003
*** Please check that your ~/.netrc file is setup correctly and has proper permissions.
***
*** see: https://oceancolor.gsfc.nasa.gov/data/download_methods/
***

Cannot create geolocation from A2012062073500.L1A_LAC; exiting.

Sir, Please provide the solution

[gnwiii]

Have you verified the contents and permissions of your ~/.netrc?   You should have:
$ cat ~/.netrc
machine urs.earthdata.nasa.gov
        login <earthdata_user>
        password <earthdata_password>
$ ls -l ~/.netrc
-rw-------+ 1 <linux_user> <linux_group> 72 Jan 21  2020 /home/<linux_user>/.netrc

At one time, I was getting login failures from oceandata.sci.gsfc.nasa.gov.  Adding a second entry with the same login and password lines, but machine oceandata.sci.gsfc.nasa.gov was needed to work around the failures. I have not needed the second machine entry recently.

If the permissions aren't correct, you may be able to correct them using:

$ chmod 600 ~/.netrc

Another potential source of failures can be problems with Windows line editing or passwords that contain non-ASCII characters with look-alike Unicode characters (dash versus minus versus em-dash, etc.).  Working in Canada, I encountered problems with a system that switched to a French keyboard when I tried to enter a password (there was a little icon that changed but it took me a while to notice).

[maheshgeotech38]

Dear Sir,
              Good evening, thank you for your great sir, followed your commands, as followed show this type of error. Please guide me on how to solve the problem.

(base) umamahesh@uma:~/Seadas_data_processing$ cat ~/.netrc
cat: /home/umamahesh/.netrc: No such file or directory

(base) umamahesh@uma:~/Seadas_data_processing$ ls -l ~/.netrc
ls: cannot access '/home/umamahesh/.netrc': No such file or directory

(base) umamahesh@uma:~/Seadas_data_processing$ chmod 600 ~/.netrc
chmod: cannot access '/home/umamahesh/.netrc': No such file or directory

[gnwiii]

See: NASA Earthdata: How to access data ... (the instructions are for wget and curl, but the OCSSW software requires the same ~/.netrc file).

[maheshgeotech38]

Dear Sir,
                 Good morning, I followed your instructions as followed by link, but my problem was not solved. Please guide me where I am doing mistakes.
I am using Ubuntu 20.04 LTS in Window10 with 12 GB RAM laptop.

https://wiki.earthdata.nasa.gov/display/EL/How+To+Access+Data+With+cURL+And+Wget

errors were

(base) umamahesh@uma:~/Seadas_data_processing$ modis_GEO.py A2012062073500.L1A_LAC
*** ERROR: Authentication Failue retrieving:
*** oceandata.sci.gsfc.nasa.gov/ob/getfile/PM1ATTNR.P2012062.0600.003
*** Please check that your ~/.netrc file is setup correctly and has proper permissions.
***
*** see: https://oceancolor.gsfc.nasa.gov/data/download_methods/
***

Cannot create geolocation from A2012062073500.L1A_LAC; exiting.

[gnwiii]

Did you review the checks in my previous post?   I have used Ubuntu 20.04 LTS with WSL2 to run modis_GEO.py using a ~/.netrc with the two machine entries.   Character set problems I mentioned can be very hard to diagnose remotely (especially as your ~/.netrc c ontains secrets so can't be posted in a forum).  One check is to log out from the forum and then log back in by pasting the username and password from your ~/.netrc.  If this fails then you know there is an issue with the ~/.netrc.

[maheshgeotech38]

Thank you, for your previous replay on L1A to L1B generation

My present Problem

I am generating Chlorophylll product from L1A different from MODIS providing Chlorophyll product, Please guide me how to generate same product as MODIS-Aqua

MODIS aqua process : l2gen par=/data4/sdpsoper/vdc/vpu7/workbuf/A2012062073500.L1B_LAC.param metafile=A2012062073500.L2_LAC_OC.nc.meta

Myself generation process : l2gen ifile=A2012062073500.L1B_LAC geofile=A2012062073500.GEO ofile=A2012062073500.L2 cloud_thresold_0.027 l2prod=chlor_a parfile=A2012062073500.L1B_LAC.anc north=17.475 cloud_thresh=0.027

Here, MODIS-A using A2012062073500.L1B_LAC.param ?? what is it ?? how we can generate it ?? Is it really possible generate like MODIS product ??

Please guide me Sir.