A Series of New Line-of-sight Wind Experiments
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This series of experiments, designed by scientists at Simpson Weather
Associates and AOML and implemented by the SIVO OSSE group, is
intended to both ensure the proper use of the line-of-sight (LOS) wind operator
in Goddard's GEOS-5 DAS and to investigate the relative contributions of 
different line-of-sight configurations on analyses of the total wind field.
These experiments are capable of being performed with real or simulated
observational data, however, current experiments use only real data (with
real data, the experiments resemble OSRE, or Observing System Replacement
Experiments, since they use real rawinsonde observations as a surrogate for
line-of-sight observations).

The initial tests were performed with the FVSSI, an interim Goddard DAS
using the NCEP SSI analysis, which is no longer available.  A resumption
of the experiments using the GEOS-5 DAS has been delayed until a tested
line-of-sight wind operator is installed in GEOS-5 through updates of
the GSI received from NCEP.

List of preliminary experiments:

CONTROL:  Uses all observations from the standard observing network
NOWIND:   CONTROL - raob winds
ULOS:     NOWIND + raob u-winds as LOS winds
VLOS:     NOWIND + raob v-winds as LOS winds
TWOLOS:   NOWIND + raob u and v-winds as LOS winds
UVLOS:    NOWIND + a blend of raob u and v-wind as LOS winds.
          The fraction of u- and v-winds is a function of
          latitude (at equator v=0, at poles u=0).