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New reprocessed Envisat GOMOS data (v6.01) accessible at D-PAC

18 December 2012

The Envisat GOMOS full-mission re-processing campaign, using the latest ESA Instrument Processor Facility (IPF) version 6.01 has been completed. After finalisation of the preliminary quality assessment, the dataset is now being released to the user community.

The new dataset covers the period from 15 April 2002 up to 08 April 2012 and comprises Envisat GOMOS consolidated Level 1b products (GOM_LIM_1P and GOM_TRA_1P) and Level 2 products (GOM_EXT_2P and GOM_NL__2P), available via ftp at the D-PAC server eoa-dp.eo.esa.int. Note, that a product format change has been applied to the data products of IPF version 6.01, as explained in more detail in the "Products format and tool" section of this user message.

Data access:

The GOMOS IPF version 6.01 dataset (Level 2) is provided at the D-PAC following the same data archive structure as previously introduced, organised per year/month/day (see news of 16 September 2011).

Level 2 GOMOS IPF version 6.01 Product Format
current/GOM_NL__2P/YYYY/MM/DD/ GOM_NL__2P_YYYYMMDD_nnnnn.tgz

current/GOM_EXT_2P/YYYY/MM/DD/ GOM_EXT_2P_YYYYMMDD_nnnnn.tgz
All IPF version 6.01 in Envisat format

Key: (where YYYY = Year, MM = Month, DD = Day, nnnnn= Orbit)

The GOMOS IPF version 6.01 dataset (Level 1b) is provided at the D-PAC on the same ftp address: eoa-dp.esa.int, with the distinctive username gomo1usr. As for Level 2, the dataset is organised per year/month/day.

Level 1b GOMOS IPF version 6.01 Product Format
current/GOM_TRA_1P/YYYY/MM/DD/ GOM_TRA_1P_YYYYMMDD_nnnnn.tgz

current/GOM_LIM_1P/YYYY/MM/DD/ GOM_LIM_1P_YYYYMMDD_nnnnn.tgz
All IPF version 6.01 in Envisat format

Key: (where YYYY = Year, MM = Month, DD = Day, nnnnn= Orbit)

Note that the previous dataset (GOMOS IPF 5.01) will still remain available until further notice at eoa-dp.esa.int with the existing account (see news from 17 October 2012).

Access to GOMOS version 6.01 level 1 and level 2 products can be provided through Fast Registration.

Level 1 Processor Upgrades

The main improvements of the GOMOS IPF v.6.01 processor compared to the previous version 5.01 are:

  • Intrapixel-PRNU (Pixel Response Non Uniformity) spectrometer B2: highly improves H2O retrieval
  • Star spectra location on CCD
  • New reflectivity Look Up Tables (LUT)
  • New slit width LUT
  • New wavelength assignment
  • Automatic dark charge bias correction
  • Update of Cosmic Ray detection and correction algorithm (twilight)
  • Correction for SATU missing data

Level 2 Processor Upgrades

  • New HRTP (High Resolution Temperature Profile) algorithm
  • New coding of errors bar (logarithmic encoding of absolute error) instead of relative error
  • The accurate characterisation of modelling errors implemented in the full-covariance-matrix inversion: impact on error estimates and X2

New Processing Identifiers

The new level 1b and level 2 datasets are identified by the new processing flag "R", replacing the flag "Q" and/or "P" used previously (e.g. GOM_TRA_1PR, GOM_NL__2PR).

The following Envisat Filename convention is valid:

    Filename and MPH:

  • Processing Stage = R
  • Processing Center = "FINPAC" ("FIN" in the Product Name)

    MPH:

  • SOFTWARE_VER = "GOMOS/6.01"
  • REF_DOC = "PO-RS-MDA-GS-2009 issue 3/K"

Products format and tool

The GOMOS IPF version 6.01 dataset applies a product format change with respect to the previous IPF version 5.01. The Product Specification document has been updated accordingly to version PO-RS-MDA-GS-2009 issue 3/K.

The following product fields have been changed (see details in the Product Specification):

  • Level 1b: new PCD flag for the dark charge bias correction
  • Level 2: new coding of the error bars of the local species density
  • Level 2: new coding of the error bars of the tangent line densities

The BEAT Software has been aligned to the new product specification as well. Download Basic Envisat Atmospheric Toolbox (BEAT)

Documentation

More detailed information on all changes implemented for the reprocessing campaign with version 6.01 is available in the dedicated Data Release Documentation online:

Product Quality Readme file (Level 1b)

Product Quality Readme file (Level 2)

Algorithm Theoretical Baseline Document (ATBD)

Product Specification

IODD

Preliminary validation reports

Verification reports

Please contact the ESA EO Helpdesk for any further information.