Fix inconsistent lat, lon azimuth when performing WO processing

[cburrows]

As Stig noted in DMI/DKC-A/TECHREP/2011/01, the sampling of lat, lon and aziumuth is inconsistent above and below the GO/WO cut-off (IH=25km by default).

It seems that in ropp_pp_occ_tool.f90 the IPs are calculated for GO, and then, for the WO processing, the IPs below 25km are overwritten with uniformly spaced levels (keeping the size of the array the same). The lats, lons and azimuths *aren't* mapped onto these levels, so the final interpolation is mismatching lat,lon,azim with the post-WO impact parameters. This would be important to fix for TPD in assimilation, and 2D operators.

There is a first attempt at a fix here (but it needs checking to ensure it is consistent with calls to ropp_pp_monotonous, though I think ropp_pp_linear_combination is OK): [4471]

[cburrows]

Output of test_pp_occ.sh before fix.

[cburrows]

Output of test_pp_occ.sh after fix.

[cburrows]

I have rebranched from the 9.0 propotype and made the change above: ​here.

The ropp_pp 'make test' failed as follows:

ERROR (from ropp_io_fields_compare):  prof1%Lev1b%lat_tp differs from prof2%Lev1b%lat_tp
 (max|diff| =  0.16887E+01 >  0.10000E-03)

ERROR (from ropp_io_fields_compare):  prof1%Lev1b%lon_tp differs from prof2%Lev1b%lon_tp
 (max|diff| =  0.44017E+00 >  0.10000E-03)

ERROR (from ropp_io_fields_compare):  prof1%Lev1b%azimuth_tp differs from prof2%Lev1b%azimuth_tp
 (max|diff| =  0.73584E+00 >  0.10000E-01)

These variables were changed deliberately so this is to be expected. No other variables failed the test.

Because of this "failure" I updated the reference data by running the make test on my branch at revision [4471] and compiling with ifort12. Apart from the lat/lon/azim differences, there are small differences to other variables in the new files, but these are generally at the machine precision level (or are downstream consequences of this). I have used these output files as the replacement reference files.

The test folder has been run (ifort12 only) for the ropp_pp tests, and the output matches that of the 9.0 prototype.

[cburrows]

This change has been successfully run through the test folder with the other updates for version 9.0. Therefore the ticket can be closed.