update GPSRO obs error and add additional data

[XuanliLi-NOAA]

Description

This update includes the following for GPSRO:

Replacing the current GPSRO observation error with the new hybrid three-cornered hat error model.
Allowing Grace-FO (SAID=803 & 804) into GSI.
Turning off the previous MetOp 8-km check.
Adding more QC categories.

More description and the results from the regression tests are included in the issue #819

Resolves #819

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• New and existing tests pass with my changes
• Any dependent changes have been merged and published

[XuanliLi-NOAA]

@RussTreadon-NOAA : Could you please add @ADCollard , @emilyhcliu , and @LidiaCucurull-NOAA as reviewers? Thank you!

[RussTreadon-NOAA]

@XuanliLi-NOAA , Lidia can not, at present, be assigned as a reviewer. She does not belong to NOAA-EMC. I sent her an invitation to be an outside collaborator with read permission. If you have not yet done so, please reach out to Lidia and share with her your request that she review this PR.

[XuanliLi-NOAA]

Thank you so much, Russ. I'll send an email to request Lidia's review on this PR.

[RussTreadon-NOAA]

WCOSS2 ctest results
Install XuanliLi-NOAA:roobserr_update at 202c7fe and develop at 27c03e8 on Cactus. Run ctests with following results

Test project /lfs/h2/emc/da/noscrub/russ.treadon/git/gsi/pr825/build
    Start 1: global_4denvar
    Start 2: rtma
    Start 3: rrfs_3denvar_rdasens
    Start 4: hafs_4denvar_glbens
    Start 5: hafs_3denvar_hybens
    Start 6: global_enkf
1/6 Test #3: rrfs_3denvar_rdasens .............   Passed  1814.82 sec
2/6 Test #6: global_enkf ......................   Passed  2063.03 sec
3/6 Test #5: hafs_3denvar_hybens ..............   Passed  2305.17 sec
4/6 Test #4: hafs_4denvar_glbens ..............   Passed  2423.50 sec
5/6 Test #2: rtma .............................   Passed  4037.12 sec
6/6 Test #1: global_4denvar ...................***Failed  4204.86 sec

83% tests passed, 1 tests failed out of 6

Total Test time (real) = 4205.06 sec

The following tests FAILED:
          1 - global_4denvar (Failed)

The global_4denvar failure is due to gpsro. The initial penalty from the XuanliLi-NOAA:roobserr_update gsi.x is significantly smaller than that from develop gsi.x. Below is a comparison of fort.212 printout for the first outer loop.

XuanliLi-NOAA:roobserr_update gsi.x

   number of gps obs failed stats qc in NH =   8253
   number of gps obs failed stats qc in SH =  11913
   number of gps obs failed stats qc in TR =  22203
 number of   gps obs extrapolated above top sigma layer=       0
           number extrapolated below bottom sigma layer=     697
 type gps_bnd jiter   1 nread    556299 nkeep  543259 num  378903
 type gps_bnd pen=  0.166230229445835896E+06 qcpen=  0.166230229445835896E+06 r=  0.438714     qcr=  0.438714

develop gsi.x

   number of gps obs failed stats qc in NH =  12174
   number of gps obs failed stats qc in SH =  15822
   number of gps obs failed stats qc in TR =  23953
 number of   gps obs extrapolated above top sigma layer=       0
           number extrapolated below bottom sigma layer=     697
 type gps_bnd jiter   1 nread    556299 nkeep  543259 num  369323
 type gps_bnd pen=  0.316549657324711443E+06 qcpen=  0.316549657324711443E+06 r=  0.857108     qcr=  0.857108

[XuanliLi-NOAA]

Let me double check the qc section, it should be about the same.

[XuanliLi-NOAA]

This is expected, I compared the numbers with those from my full resolution experiments. They are comparable. Penalty is smaller because of the larger obs error.

[LidiaCucurull-NOAA]

The changes look good. Please, double check the type of processing for GRACE-FO and Sentinel-6 in read_gps.f90. I believe these missions are not processed by UCAR/CDAAC, but unless I am reading it wrong, they are under the CDAAC group.
Also, you might want to consider removing new QC=7 since MetOP data is no longer rejected (and biases for future EPS missions will no longer exist either). Finally, the header text in setupbend.f90 seems to suggest that GRACE-FO is only assimilated below 8 km (the "< 8km" should be removed.)

[XuanliLi-NOAA]

@LidiaCucurull-NOAA , I just want to confirm, should we switch GRACE-FO and Sentinel-6 from the pccf to qfro check? Or should we remove them from both checks? They should have a quality flag.

[LidiaCucurull-NOAA]

Xuanli and I met today. We discussed the code changes and some of my previous comments. I will check on which are the processing center for satellites ids 803, 804 and 66 to identify the right QC process to follow in read_gps. Also, it appears that the variable "repe_gps" is no longer used in setupbend.f90 with the new hybrid error model. Xuanli will test the code with the removal of this variable (which currently needs to be computed for each individual observation within a profile). This would save computational time and would make the code cleaner.