TOSOMI algorithm version history

Henk Eskes and Ronald van der A, KNMI

• FRESCO SC-v6 used
• Correction of the reading of surface reflectivity data
• Only version 7.03/7.04 level 1 files used

• Corrected temperature files used
• Only version 6.03 level 1 files used

• Data files polycoef_trs_scia.dat and polycoef_R1_scia.dat added for use by FRESCO+.
• FRESCO+ (SC-v5) replaces FRESCO SC-v4:
  new FrescoModule.f90
  new sciaFrescoInterface.f90 (line 134-139, 195-209)
  atmosphere_height from 50 km to 0 km (line 306)
  
• "writeOutputModule" header line updated

Cross sections: GOME Flight Model 98 cross sections are replaced by effective cross sections based on Bass-Paur high resolution data
Bass, A.M., and Paur, R.J., Proc. Quadrennial Ozone Symp., Chalkidiki, Greece, Eds. C. Zefros and A. Ghazi. 1986

• Obsolete Cabannes correction factors removed
  ComputeAmfModule.f90, line 252
• Added cycle command in "main.f90"
  if (SciaPixelOut%amfQa < 0 ) cycle
  This to skip the current observation in case the AMF is undefined,
  e.g. because input parameters are out of range
• sciaReadModule.f90
  added correction to compensate for the mismatch between the detector
  readout time and the time at which the geometrical information is provided.
  l 373, 374: definition of parameters
  l 609-643 : implements the correction for the vza at satellite "dVzaSat"
  For the evaluation of "isBackScan" the longitude/latitude information
  and scanmirror angle is needed. The calculations for this have been
  moved up (l 504-553).
• "writeOutputModule" header line updated

• The NASA toolbox has been replaced by a toolbox simulator module for portability reasons.
• The spectral reflectivity data base for the FRESCO algorithm is upgraded to a 0.25 degree resolution map (by Nicolas Fournier)
• FrescoModule.f90, line 1585
  Small bug fix in FRESCO
• sciaArrayDimsModule, line 21
  Maximum number of SCIAMACHY pixels has been increased
• sciaFrescoInterface, line 262
  Radiometric calibration fudge factor is changed from 1.25 to 1.2 for the FRESCO algorithm
• terrainHeightModule, line 12
  The terrain height map resolution has increased to 0.25 degree
• toolkitSimulator
  This is a new module
• A few error messages have been replaced by warnings

First validated data available on TEMIS

• A check is included on the version of the level 1 file.
  "sciaReadModule": the angle conversion is now depending on L1_soft_version
• sciaUtilityModule: now contains extra routine
  "RecoverSolarAnglesAtSat2"to convert angles from TOA to satellite.
• sciaReadModule: now includes a call to "check_data_validity", which checks the range of the geolocation parameters
• sciaReadModule: A "fudge factor" of 1.19 is introduced to correct for the SCIAMACHY missing radiance.
• The centre coordinates (longitude) of the pixels had a problem near the date line. This coordinates was simply taken from the level-1 file and copied to the output file.
  For pixels on the date line, the longitude is now recomputed based on the pixel corner coordinates:
  sciaPixel%longitude(5) = sum(sciaPixel%longitude(1:4))*0.25
• sciaReadModule.f90
  lines 597-619
• writeOutputModule.f90
  new output format (units 0.1 DU)
• The Sciamachy L1 reading libraries have been replaced. The new library checks consistency between header and data, and checks for empty files.
• In case of errors the program will produce an exit status = 1 "stop" statement replaced by "call exit(1)"

A spherical geometrical air-mass factor is introduced to reduce solar-zenith angle dependent interpolation errors in determining the air-mass factor. The input air-mass factor tables are updated and contain AMF(Empyrical,DAK)/AMF(Geometric,spherical) instead of AMF(Empyrical,DAK)/AMF(Geometric,plane parallel)

• computeAmfModule.f90
  The call to "computeAmfGeo" is replaced by "computeAmfGeoSpherical"
  A new subroutine "computeAmfGeoSpherical" is added.

Version 0.3 contains new lookup tables based on semi-spherical DAK (Johan de Haan).
These tables replace the old ones:
data/AmfClear_325_335.h4
data/AmfCloudy_325_335.h4
The old plane-parallel lookup tables are still available as
data/AmfClear_325_335_PP.h4
data/AmfCloudy_325_335_PP.h4

• readSciaModule.f90:
  The lookup table angles are defined at the Earth's surface
  line 473: dAtmosphereHeight = 0.0d0
• sciaFrescoInterface.f90:
  line 261:
  ! The extra factor 1.25 accounts for problems with the
  ! radiometric calibration of Sciamachy
  erad(i)=1.25*erad(i)
  line 266:
  if ( firstcall ) then
  print*,'sciaFrescoInterface WARNING: ',&
  'scaling factor 1.25 applied to account for calibration errors'
  end if
  
• sciaFrescoInterface.f90:
  A larger radiance error improves the Fresco performance, factor 0.005->0.05
  line 261:
  errerad(i)=erad(i)*0.05
  
• writeOutputModule.f90:
  A 7-line header is added to the data file, with processor version + authors
  
• dataModule.f90:
  fields "product" and "soft_version" added to "SciaL1RadGenType"
  
• "bin/sciadto.opf"
  contains extra field "SZA_MAX" set to 85.0 degree
  "getOpfModule.f90"
  reads the variable "opfData%szaMax"
  "dataModule.f90"
  variable "opfData%szaMax" added
  "main.f90"
  implements check on the solar zenith angle - "szaMax"
  
• "sciaUtilityModule.f90"
  extra subroutines "asin_" and "acos_" are defined to avoid NaNs due to over/underflow of the argument. These alternative routines are used in the angle manipulation subroutines.
• "frescoModule.f90"
  Extra output flag value "xflag=5" introduced to intercept errors in "gaussjf" related to singular matrices. Numerical recipes subroutine now passes it's error by the variable "istatus"
• "sciaFrescoInterface.f90"
  An extra variable has been added to "acceptFrescoRetrieval" to account for the new Fresco error warning.