MODIS-T XCAL v4.9b / v4.10b cause mismatch in ntime in l2gen (OCSSW V2025.5)

[johan_ma]

Dear OCSSW team,

I encountered a reproducible issue when processing MODIS-T data in 2019 using OCSSW V2025.5. MODIS-A does not have this problem.
The l2gen task fails with the following message:

Loading XCAL rvs and polarization sensitivities from
/home/johan/ocssw/var/modist/xcal/OPER/xcal_modist_txc_oc_v4.9b_412.hdf
-E- /accounts/dshea/ocssw/oel_hdf4/libl1/xcal.c Line 148: mismatch in ntime

This error occurs consistently on two different machines, both using clean installations of OCSSW V2025.5.

Interestingly, older setups (using the V2025.5 tag, but still referencing
`xcal_modist_txc_oc_v4.7b_*.hdf`) work fine. After manually replacing the 4.9b files
with the older 4.7b series, the issue disappears completely.

It seems that the current OCSSW distribution is pulling in an incompatible XCAL bundle
(v4.9b) for MODIS-T, which causes structural mismatches in the time dimension.

Could you please confirm whether the v4.9b XCAL files are intended for the current MODIS-T
code, or if this was an accidental update mismatch? I try v4.10b but have same problem.

System info:
- OCSSW tag: V2025.5
- Platforms tested: Ubuntu 22.04 (WSL2)
- Command used: `l2gen ifile=... geofile=... ofile=...`

Thanks for your attention and for maintaining OCSSW!

[OB SeaDAS - dshea]

The problem is that we did not expect Terra to last this long... We only had space in the code for 300 date records and the current xcal file for modist (xcal_modist_txc_oc_v4.12b) has ndates = 307. The fix for this first appearers in T2025.16 so any tag after that should work. Sorry it is not in any "V" tag you have access to.

don shea