Total Ozone Content from the NOAA/TOVS data: data set description page


Data set source
Information on available Data
Data Processing
Data format
References
Data selection page
The NOAA/TOVS Total Ozone Content Product was prepared by Fernand KARCHER, Meteo-France/CNRM, from the NOAA/TOVS raw data (level-1b files) produced by the NOAA/NESDIS for the 2 NOAA polar orbiting satellites NOAA-12 and NOAA-14.

Data set source

  • NOAA polar satellites


    • Information on available data in the FASTEX Central Archive

  • between 19970101:00Z and 19970301:00Z
  • Data included in the FASTEX area (20N-90N, 140W-40E)


    • Data processing:

    The infrared radiances measured by the TIROS Operational Vertical Sounder/ High-resolution Infrared Sounder 2 (TOVS/HIRS2) on NOAA-12 and NOAA-14 were acquired daily at NOAA/NESDIS. Meteo-France/CNRM received the level-1b data from NOAA/NESDIS through ECMWF. The method of retrieval used the Channel 9, centered on the ozone absorption band at 9.6 micrometers, the window Channel (8) at 11 micrometers, and the Channels 2 (14.7 micrometers) and 6 (13.7 micrometers). A complete description of the method is in Lefevre et al (1991).

    Spatial resolution

    The HIRS2 scans perpendicularly to the orbit, its spatial resolution ranging from 25x42 km at nadir to 78x42 km at the extremity of the scan. Ground Instantaneous Field of View (IFOV) at nadir is 17.4 km (diameter). At end of scan it is 58.5 km cross-track and 29.9 along-track. Total Ozone data refer to these IFOV.

    Domain:

    A data file contents the data from one satellite pass, when they are included in the FASTEX area (20N-90N, 140W-40E).

    Data format

    Each file name *.dat is made by appending the satellite identifier, the product identifier and the Date/Time of the first data in the file (example: nj_ozo_9702212357.dat). The satellite identifier is nd for NOAA-12, nj for NOAA-14.

    Format description :

    Each ASCII file contains a header of 1 line, and N data records.
    The header line includes the Date/Time of the first data in the file.
    Each data record contains 4 fields, separated by spaces. The contents and sizes of the 4 fields are as follows (Unit for Unit, Form for FORTRAN Format, Miss for Missing value). 
     No Parameter                           Unit           Form. Miss
 -- ---------                           ----           ----- ----

  1 Latitude (centre of IFOV)           dec.degrs      f6.2
  2 Longitude(centre of IFOV)           dec.degrs      f7.2
  3 Collecting Time (UTC)               HHMISS         a6
  4 Total Ozone Content                 Dobson         i3

FORTRAN Format for a data record:
(f6.2,1x,f7.2,1x,a6,1x,i3)

    References

    Lefevre, F., D. Cariolle, S. Muller, and F. Karcher: Total ozone from TOVS/HIRS2 infra-red radiances during the formation of the 1987 'ozone hole', Journal of Geophysical Research, 96, 12893-12911, 1991.
    Updted: 18 Mar 1998

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