Update to RTTOV v10.2 - 10th April 2012
---------------------------------------

1. Applying the update

The update file is called rttov102_update_20120410.tar.gz. This update includes
modified source files, updates to affected test reference data, and a renamed
version of the sentinel-3 SLSTR coefficient file (see below).

To apply the update, copy the tarball into your top-level RTTOV v10.2 directory
and unzip it. For example:

$ cd ~user/rttov102
$ tar -zxf rttov102_update_20120410.tar.gz

Then remove one obsolete file and recompile:

$ cd src
$ rm -f main/rttov_integrate_mod.F90
$ make ARCH=myarch


2. Bugs/issues fixed by the update

The significant fixes/updates included are listed below:

Compilation failure affecting certain compilers/architectures:
- updates to rttov_integrate_ad/k to fix this.

Update to ensure code is thread-safe in all parallel implementations:
- for v10.2 the subroutine rttov_integrate was re-written as a module
  (rttov_integrate_mod.F90). The OpenMP "THREADPRIVATE" directive was used to
  protect module-level variables in parallel implementations. This should be
  fine for OpenMP, but is not guaranteed thread-safe if users run RTTOV with
  alternative parallelization methods. There have been no reports of errors, but
  this update removes any doubt. NB As a result of this change the file
  rttov_integrate_mod.F90 has been renamed back to rttov_integrate.F90.

IR emissivity atlas: 
- returned emissivities were shifted 0.05 degrees in latitude and longitude due
  to a rounding error.

Shortwave IR solar simulations, sea surface reflectance calculation:
- error in coding of TL/AD/K (the impact of this bug is small)
- when the horizontal 10m wind speed was zero the wind direction was incorrectly
  specified.
- users should be aware that the way azimuth angle is defined for shortwave IR
  solar simulations differs to that for FASTEM emissivity calculations. For
  solar simulations, the satellite and solar azimuth angles are defined as in
  section 2.1 of the user guide: measured anti-clockwise from the local eastward
  parallel (i.e. east = 0, north = 90 degrees). For FASTEM, the satellite
  azimuth angle is measured as described in Annex V: measured clockwise from the
  local northward meridian (i.e. north = 0, east = 90 degrees). One single
  definition of azimuth angle will apply throughout the code in RTTOV v11, but
  for consistency these different definitions are retained in v10.2.

PC simulations with reconstructed radiances:
- a bug has been fixed whereby an attempt was made to access an unallocated
  array when running the PC-RTTOV K model with reconstructed radiances where no
  input CO2 profile is supplied.

Instruments/platforms:
- The "sentinel" platform (currently used for the SLSTR instrument in RTTOV) has
  been renamed "sentinel3". The SLSTR coefficient file has therefore also been
  renamed and the updated file is supplied with this update (the coefficients
  have not changed).
- IDs have been added for the NIMBUS platform and the SCAMS and SMMR instruments
  in preparation for coefficient file generation in support of reanalysis
  projects.


3. Contents of the update

The file rttov102_update_20120410.tar.gz contains:

readme_rttov102_update_20120410.txt
rtcoef_rttov10/rttov7pred51L/rtcoef_sentinel3_1_atsr.dat
rttov_test/test_emisatlas.2/*
rttov_test/test_rttov10_hires.2/*
rttov_test/tests.0/slstr/*
src/coef_io/rttov_read_ascii_sccldcoef.F90
src/emis_atlas/mod_iratlas.F90
src/main/Makefile
src/main/rttov_const.F90
src/main/rttov_direct.F90
src/main/rttov_integrate.F90
src/main/rttov_integrate_ad.F90
src/main/rttov_integrate_k.F90
src/main/rttov_integrate_tl.F90
src/main/rttov_mult_profiles_k.F90
src/main/rttov_refsun.F90
src/main/rttov_refsun_ad.F90
src/main/rttov_refsun_k.F90
src/main/rttov_refsun_tl.F90
src/mw_scatt/Makefile
src/mw_scatt_coef/channels.dat_all
src/parallel/Makefile
src/test/Makefile