RFM Driver Table Sections

*SPC Section: Spectral Range & Resolution

02SEP05
Type
Primary Section#3

Description:
Define range(s) and resolution(s) of output spectra generated by RFM.
Units are [cm-1] by default, or [GHz] if the GHZ flag is enabled.

Format
Multiple records, order may be significant.
There are four types of record whose structure is determined by the number of fields (1-4) contained in the record (the 3 or 4-field records are probably what you want)
  1. FILSPC
  2. LABSPC RESSPC
  3. LOWSPC UPPSPC RESSPC
  4. LABSPC LOWSPC UPPSPC RESSPC
Field Type Description Range
FILSPC C*80 Name of a .spc file
LABSPC C*8 Label for spectral range
RESSPC R*8 Resolution [cm-1] of output spectra 0.0004 (=1/MAXFIN):1.0
I N.Pts/[cm-1] of output spectra 1:2500 (=MAXFIN)
LOWSPC R*8 Lower wavenumber [cm-1] for output spectra 0.001 - UPPSPC
UPPSPC R*8 Upper wavenumber [cm-1] for output spectra LOWSPC - 20000

Notes
  1. The RFM calculates each spectral range sequentially in the order in which they appear in this section, but the results do not depend on the order. There are no benefits other than convenience in specifying more than one spectral range within a particular driver table.
  2. FILSPC: a single field in the record is interpreted as the name of a .spc file containing predefined spectral ranges and resolutions.
  3. The LABSPC spectral range labels can contain up to 8 characters (no internal spaces). These are case-sensitive and appear as part of the output filenames, so labels are compulsory if more than one spectral range is required (so that the different output files are distinguished).
  4. It is possible to have different LABSPC labels identifying the same upper and lower limits provided the resolution is different.
  5. Predefined LABSPC labels may be redefined (with a warning in the rfm.runlog file), but once the resolution has been set the label may not be further redefined.
  6. RESSPC values < 1 are interpreted as resolution in [cm-1] while values > 1 (integers) are interpreted as `number of points per wavenumber' (ie reciprocal of the resolution). If the GHZ Flag is selected, the value is interpreted literally as GHz (30GHz = 1cm-1 approx).
  7. Setting RESSPC = 0 is the method for predefining a range without actually initiating a calculation. This would normally only be done in a .spc file. To activate it, the LABSPC is quoted again, but with a non-zero resolution (using a 2-field record)
  8. The RESSPC resolution applies to the output spectra - if an ILS convolution is required the RFM by default performs internal calculation at 0.0005 cm-1 resolution (use the FIN Flag to alter this) or the closest sub-multiple of the output spacing.
  9. A warning message is printed in the rfm.runlog file if spectral lines at the highest required tangent level are unlikely to be unresolved at the resolution selected for the fine-mesh calculation (ie RESSPC in the absence of any ILS convolution).
  10. The maximum resolution RESSPC is determined by the value of MAXFIN parameter in rfmsiz.inc
  11. The limiting values for LOWSPC and UPPSPC are set in spcchk.for and are basically just sanity checks (although a value 0cm-1 causes problems).
  12. If the GHZ Flag is enabled the requested spectral range and resolution are converted to wavenumber internally (30GHz approx 1cm-1) and the calculation proceeds in the same way.

Examples
This is a single, user-specified, unlabelled spectral range 
*SPC   
    1020 1030 0.01     ! 1020-1030 cm-1 @ 0.01 cm-1 resolution
This is a pair of labelled spectral ranges @ 40pts/wno. 
*SPC
    BandA  685  970 0.025  ! Band A
    BandB 1215 1500 0.025  ! Band B
The next example uses preloaded ranges and multi-range RFM calculation. In this case the file amicro.spc would contain a series of predefined spectral ranges (see example .spc file) 
*SPC   
    amicro.spc              ! Define MIPAS A band microwindow spectral ranges
    PT001A 2000             ! Microwindow 'PT001A' @ 0.0005 cm-1 resolution
    A15HR 952   953.2 0.001 ! A15 Microwindow @ 0.001/cm resolution
    A14   944.5 946.5 0.001 ! Redefine A14 range and run @0.001/cm resolution
The A15 range is activated by the second record, and the third record runs another calculation over the same range but at a different resolution, requiring a new label to be defined to prevent conflict over output filenames.

Bugs
Bug#51 (Fixed v4.25)
Bug#47 (Fixed v4.23)
Bug#38 (Fixed v4.22)
Bug#17 (Fixed v4.11)
Bug#15 (Fixed v4.11)
Bug#7 (Fixed v4.10)