[Dart-users] minor updates to obs_def files

[Nancy Collins]

  hello dart users,

i've just committed 2 updates to the dart obs_def dir.

one adds DROPSONDE_xx as a possible observation
type for temperature, U, V winds, surface pressure,
relative & specific humidity, dewpoint, and altimeter.
when you create observations you can now distinguish
between RADIOSONDES and DROPSONDES if that's a
useful distinction in your experiments.

the other change collects all the various DEWPOINT obs
types into the existing obs_def_dew_point_mod.f90 file.
these were previously spread out between the gts,
the metar, and the reanalysis_bufr obs_def files.
in some cases these files were set up to call the model
directly in the case of a DEWPOINT observation, trying
to interpolate the value directly from a DEWPOINT field,
instead of calling the normal forward operator code
which does the calculation based on pressure and
water vapor mixing ratio.  in the updated files, all
DEWPOINT types now call the same forward operator code.

i've also updated two input.nml files that did not include
the dew point module in the &preprocess namelist.
if you have code which uses DEWPOINT obs and if after
you update you get an error, add this line to the
&preprocess_nml section in your input.nml and rerun
quickbuild.csh again:

&preprocess_nml
  ...
  input_files = (whatever you had before, plus),
                '../../../obs_def/obs_def_dew_point_mod.f90'
  /

contact me in case of any problems,
nancy