README for PFM_LOW

This README_PFM_LOW file describes file contents.

The form of the data:

text form devided with comma;i.e. comma-separated text data

The parameter included in each line:

Channel number,Scaled Sub-Wavelength,Integral response value for sub-wavelength

1. Sub-wavelength

   Sub-wavelength is the divided wavelength within effective response range for each GLI channel and it is defined as follows.

   SWL(I,CH)=WL(CH)+DW(CH) × RX(I,CH)

   SWL	: Sub-wavelength [µm]
   WL	: Center wavelength [µm]
   DW	: Scaling factor [µm]
   RX	: Scaled sub-wavelength
   I	: Consecutive division number (I=1 to NW0)
   CH	: GLI channel
   NW0	: Number of the sub-wavelength

   The sub-wavelength was decided in accordance with the following procedure.

   a) Determination of the effective response range.

   We defined the effective range, which consists of in-band and out-band, as follows.

   In-band	: twice the half-width (50% of maximum transmittance) centered on maximum transmittance.
   Out-band	: such a wavelength range as the transmittance value is greater than 10-5 on each side of the in-band.

   But, if the right side of the out-band is less than " WL + 4 × half_width " and the left side of the out-band is greater than "WL - 4 × half_width", the each sides are assigned to "WL + 4 × half_width" and "WL - 4 × half_width" respectively.

   b) Division of the effective range.

   We divided the in-band into seven equal regions and the out-band into fourteen equal regions.

    

2. Integral response value for sub-wavelength

   The integral response RF(I) was integrated in accordance with the following definitions.

   Integral range	: "Sub_wl(I) - {Sub_wl(I) - Sub_wl(I - 1)} / 2" to "Sub_wl(I) - {Sub_wl(I + 1) - Sub_wl(I)} / 2 + 0.1"
   Method	: trapezoid approximation (0.1[nm] width)

by NASDA/RESTEC 1999. 10. 7