Ticket #433: grassaf_invert_cntl.cf

# $Id: $

#****c* Configuration Files/romsaf_invert.cf *
#
# NAME
#    romsaf_invert.cf - ROM SAF inversion default parameter settings
#
# SYNOPSIS
#    <pp_program> ... -c romsaf_invert.cf ...
# 
# DESCRIPTION
#    This file reflects the configuration for the PP
#    implementations within ROPP consistent with ROM SAF inversion data.
#
# NOTES
#
# AUTHOR
#   Met Office, Exeter, UK.
#   Any comments on this software should be given via the ROM SAF
#   Helpdesk at http://www.romsaf.org
#
# COPYRIGHT
#   (c) EUMETSAT. All rights reserved.
#   For further details please refer to the file COPYRIGHT
#   which you should have received as part of this distribution.
#
#****

#-------------------------------------------------------------------------------
# 0. Output options
#-------------------------------------------------------------------------------
output_tdry = .true.        ! Flag to output dry temperature
 
output_diag = .false.       ! Flag to output additional diagnostics

#-------------------------------------------------------------------------------
# 1. Excess phase to bending angle processing
#-------------------------------------------------------------------------------

# 1.1 Occultation processing method
# ---------------------------------

# GO - use GEOMETRIC OPTICS processing to derive bending angle as a function of 
#      impact parameter from excess phase as a function of time.
# WO - use WAVE OPTICS (CT2 algorithm) processing to derive bending angle as a 
#      function of impact parameter from excess phase as a function of time.

occ_method = WO

# 1.2 Filtering method
# --------------------

# optest - use OPTIMAL ESTIMATION: solution of integral equation
# slpoly - use SLIDING POLYNOMIAL

filter_method = optest

# 1.3 Smoothing bending angle profile
# -----------------------------------


fw_go_smooth = 3000.0   # Filter width for smoothed GO bending angles (m)

fw_go_full  = 3000.0    # Filter width for full resolution GO bending angles (m)

fw_wo = 2000.0          # Filter width for wave optics bending angle above 7 km(m)

fw_low = -1000.0        # Filter width for wave optics bending angle below 7 km (m)

# 1.4 Maximum height for wave optics processing
# ---------------------------------------------

hmax_wo = 25000.0      # Maximum height for wave optics processing (m)

# 1.5 Data cut-off limits
# -----------------------

Acut     = 0.0        # Fractional cut-off limit for amplitude

Pcut     = 0.0        # Cut-off limit for impact height

Bcut     = 0.2        # Cut-off limit for bending angle

Hcut     = -999000.0  # Cut-off limit for straight-line tangent altitude

# 1.6 CT2 options
# ---------------

CFF      = 2        # Complex field filter flag (CFF = 'P')

dsh      = 100.0    # Shadow border width (m)

# 1.7 Degraded L2 data flag
# -------------------------

opt_DL2  = .true.

# 1.8 Compute and output spectra flag
# -----------------------------------

opt_spectra = .false.

# 1.9 Paths to EGM96 geoid model coefficients and corrections file
# ----------------------------------------------------------------

egm96 = ../data/egm96.dat                 # EGM96 coefficients file
 
corr_egm96 = ../data/corrcoef.dat         # Correction coefficients file

#-------------------------------------------------------------------------------
# 1. Ionospheric correction processing
#-------------------------------------------------------------------------------

# 1.1 Ionospheric correction method
# ---------------------------------

# GMSIS - use MSIS climatology bending angle (searching global MSIS profiles
#         for best fit profile to obs) in ionospheric correction, 
#         statistical optimization and bending angle to refractivity inversion.
#
# MSIS - use MSIS climatology bending angle in ionospheric correction, 
#        statistical optimization and bending angle to refractivity inversion.
#
# BG   - use climatology from a specified input file containing 
#        background temperature, pressure and humidity 
#        (e.g. from an NWP analysis). The input filename can be specified 
#        using the '-bfile' command line argument or setting 'bfile' (see 1.5).
#
# NONE - linear combination of L1 and L2 bending angles in ionospheric 
#        correction, no additional information above observed profile top
#        in the inverse Abel to compute refractivity.
 
method  = GMSIS                # Ionospheric correction method

# 1.2 Abel integral method
# ------------------------

# LIN  - assume linear variation of bending angle and ln(n) between 
#        observation levels. This algorithm is used in ROM SAF NRT processing
#
# EXP  - assume exponential variation of bending angle and ln(n) between 
#        observation levels. This algorithm is used in ropp_fm module.

abel = LIN

# 1.3 Statistical optimisation method
# -----------------------------------

# SO  - statistical optimisation.
# LCSO  - linear combination plus statistical optimisation.

so_method = so 

# 1.4 MSIS model coefficients file
# --------------------------------

mfile    = MSIS_coeff.nc       # Model coefficients file

# 1.5 Background model temperature, humidity, pressure file
# ---------------------------------------------------------

bfile    = BG_file.nc       # Background meteorology profile file (method=BG)

#-------------------------------------------------------------------------------
# 2. Impact parameter grid
#-------------------------------------------------------------------------------

# The ionospheric correction interpolates L1 and L2 bending angle profiles onto a 
# standard grid. 

dpi = 100.0             # Step of standard impact parameter grid (m)

#-------------------------------------------------------------------------------
# 3. Smoothing bending angle profile
#-------------------------------------------------------------------------------

# A smoothed bending angle profile is derived compute the fit of observed bending 
# angles to the model bending angle profile.

np_smooth = 3           # Polynomial degree for smoothing regression

fw_smooth = 1000.0      # Filter width for smoothing profile

#-------------------------------------------------------------------------------
# 4. Model bending angle profile fit to observations
#-------------------------------------------------------------------------------

# To avoid systematic deviations from the observed profile with MSIS climatology,
# the model profile is scaled to the observed profile by a fitting coefficient, 
# computed by regression.

nparm_fit = 2           # Number of parameters for model fit regression

hmin_fit  = 40000.0     # Lower limit for model fit regression

hmax_fit  = 60000.0     # Upper limit for model fit regression

omega_fit = 0.3         # A priori standard deviation of regression factor

#-------------------------------------------------------------------------------
# 5. Ionospheric correction and statistical optimization
#-------------------------------------------------------------------------------

# The method described by Gorbunov (2002) is implemented to perform ionospheric
# correction with statistical optimization. 

f_width = 250.0         # Ionospheric correction filter width

delta_p = 100.0         # Step of homogeneous impact parameter grid

s_smooth = 2000.0       # External ionospheric smoothing scale

z_ion = 50000.0         # Lower height limit of ionospheric signal

z_str = 35000.0         # Lower height limit of stratospheric signal

z_ltr = 12000.0         # Lower height limit of tropospheric signal

n_smooth = 11           # Number of points for smoothing (must be odd)

model_err = -0.5        # A priori model error std.dev. (dyn.est. if negative)

#-------------------------------------------------------------------------------
# 6. Bending angle inversion to refractivity
#-------------------------------------------------------------------------------

# The Abel inversion is computed to retrieve refractivity from corrected 
# bending angles. If method=MSIS, the corrected bending angle profile is extended 
# using MSIS data above the observed profile top.

ztop_invert = 150000.0  # Height of atmosphere top for inversion

dzh_invert = 50.0       # Step of inversion grid above observation top

dzr_invert = 20000.0    # Interval for regression in inversion