Hi,
Our Terra L1B data have not processed since 2/16.  According to the SeaDas logs, L1A processing completes and the geolocation file is created,  Modis_L1A_to_L1B fails. It suggests looking at LogStatus and LogUser files, which I've done. Here's the error-

Calculate_RVS_Correction():MODIS_F_OUT_OF_RANGE:295735301
:MODIS_F_OUT_OF_RANGE:295735301
Out of range running...MOD_PR02. TIME:Fri May 15 00:18:58 2009
Operator Actions:
Check previous messages to identify LUN of the file and other possible causes.
Contact MCST.
Also contact SDST if the LUN corresponds to a MOD01 or MOD03 granule.

The luts, utcpole and leapsec are updating normally, and nothing else was changed, it just stopped working correctly. Can you fill me in on what the error message means? What is LUN, who is MCST, SDST and how do I contact them? More importantly, what can I do to correct the problem?

Thank you for any assistance you can provide.

We're running Seadas 5.

If you're not running SeaDAS 5.3 then that could be the problem, so if you're using an older version please install SeaDAS 5.3 (do this in a new separate directory) and try again.

Our IT department will have to attend to that, which could take some time. In the meantime, is there a reason Terra would stop processing all of a sudden in February using Seadas 5? My direct broadcast Aqua data is processing fine, so I'm a bit suspicious that the version is the problem.  Can you fill me in on what the error refers to for future reference?

You've not given us the full version number of seadas.  There is 5.0, 5.1, 5.2, and 5.3.  With various updates in between, depending on the version.  So exactly what version are you running?  I suspect you are right that the version is the problem.  That's why Mike suggested that you update to the most current version.  That would be the only way to fix this problem.  It is a matter of data files and software being unable to handle the data past a certain point.  See here:

http://oceancolor.gsfc.nasa.gov/forum/oceancolor/topic_show.pl?pid=9025

The bottom line is that you aren't going to be able to fix this until at least you update to 5.3.

Mark

It's version 5.0, which is installed on our production machine. I have 5.3 installed on my local machine, and the test files processed fine, so suspicion confirmed. Our servers are managed by the IT team, so I'm on their schedule, but at least I can run data locally in the interim. Still curious exactly what is failing though, other than just something to do with 5.0.  The less black box something is, the more confident I am in our processing. Will post an update when 5.3 is installed. Thanks to you both for your replies, Lisa

The issue is with the magnitude of the change in response versus scan angle, which is increasing with time.  The MCST code had some thresholds defined to flag/fail anomalously large change in RVS.  This threshold was too restrictive for the magnitude of change seen late in the mission, and the RVS began to exceed it routinely.  I am surprised you did not see this sooner, as it brought all operational MODIS processing to a standstill about 1.5 years ago. SeaDAS 5.1 contains the update to the RVS thresholds.

-- bryan

Such MODIS pre-Level-1B problems can be difficult to diagnose especially because we don't maintain the original science code for MODIS L0->L1B. This is why we sometimes first say "please just upgrade". Some more details from our MODISL1DB release notes:

> MODISL1DB 1.4.1 released September 25, 2007
>
> The only change for version 1.4.1 is an updated terra_l1bgen binary.
> This update fixes a problem in the MOD_PRO2 (terra_l1bgen) processing
> code that was causing MODIS-Terra L1A to L1B processing to fail
> depending on which calibration LUT versions were being used. The issue
> was determined (by MODAPS and the OBPG) to involve the RVS correction
> limits set in the PreprocessP.h file. The threshold values have been
> relaxed in the PreprocessP.h header file from:
>
> #define RVS_CORRECTION_UPPER_LIMIT  1.2e+0
> #define RVS_CORRECTION_LOWER_LIMIT  8.0e-1
>
> to:
>
> #define RVS_CORRECTION_UPPER_LIMIT  2.4e+0
> #define RVS_CORRECTION_LOWER_LIMIT  4.0e-1
>
> This change appears to fix the problem. The new terra_l1bgen binary
> should now work with any past and future calibration LUTs.

Upgraded to Seadas 5.3, problem solved. Terra and Aqua are now processing. Thanks again for the responses.