README.md changed (add some cautions)

README.md

@@ -91,7 +91,7 @@ In this section, users can describe the target information including target magn
 | LINE_FLUX       | 1.0e-17       | Emission line flux          | [erg/s/cm^2]          |
 | LINE_WIDTH      | 70            | Emission line width sigma   | [km/s]                |
 
-Note: You can input your own target spectra into the ETC. Just specify the file name for `MAG_FILE`. The file should include wavelength [nm] and magnitude [ABmag] in the first and second column, respectively. Please note that the wavelength is resampled with the sampling of 0.5A which is slightly larger than the pixel sampling of the PFS detector (~0.7A, ~0.8A, and ~0.8A for blue, red, and NIR arm, respectively). We do not recommend to include "NaN" or other non-numeric values in the input file.
+Note: You can input your own target spectra into the ETC. Just specify the file name for `MAG_FILE`. The file should include wavelength [nm] and magnitude [ABmag] in the first and second column, respectively. Please note that ETC does not convolve the instrument resolution to the input spectrum internally, so the resolution should be considered in the input spectrum in advance. Also note that the wavelength is resampled with the sampling of 0.5A which is slightly larger than the pixel sampling of the PFS detector (~0.7A, ~0.8A, and ~0.8A for blue, red, and NIR arm, respectively). We do not recommend to include "NaN" or other non-numeric values in the input file.
 
 ### Setup of the name of the output file
 The outputs of the calculation are saved to the files defined by users. `OUTFILE_NOISE` defines the file name for the outputs of the noise calculation, `OUTFILE_SNC` defines the file name for the continuum S/N, and `OUTFILE_SNL` is for the emission line S/N. If you want to measure the S/N for [OII] doublet, kindly use `OUTFILE_OII` for the output file. If you set `NOISE_REUSED` to Y, the ETC will skip the process of generating noise vector which is a time-consuming process. The process time of the ETC can be reduced to roughly half by this mode. This mode is useful if you want to calculate the S/N of objects with various magnitudes and line fluxes with the same noise assumption (zenith angle, field angle, lunar condition, and exposure time). If you use this mode, you need to specified the noise vector file that you want to use in `OUTFILE_NOISE`. Also, You can skip outputting the results of continuum S/N and emission line S/N by replace the name to '-'. If you want to use medium resolution mode in the red arm, set `MR_MODE` to Y.
@@ -160,7 +160,7 @@ d. `OUTFILE_OII`: S/N of [OII] emission lines (here we assume line ratio is 1:1)
 Some caution again:
 
 1. `NOISE_REUSED` option is only valid for the same condition (zenith angle, field angle, lunar condition, and exposure time). Please be careful when you use this option and DO NOT use the different values from those used when the noise file was created.
-2. You can input your own spectra by using `MAG_FILE` option, but please note that the wavelength sampling should be larger than the pixel sampling of the PFS detector (~0.7A, ~0.8A, and ~0.8A for blue, red, and NIR arm, respectively).
+2. You can input your own spectra by using `MAG_FILE` option, but please note that ETC does not convolve the instrument resolution to the input spectrum internally, so the resolution should be considered in the input spectrum in advance. Also note that the wavelength sampling should be larger than the pixel sampling of the PFS detector (~0.7A, ~0.8A, and ~0.8A for blue, red, and NIR arm, respectively).
 
 Spectral Simulator 
 ------------------
@@ -186,7 +186,7 @@ So, before running gen_sim_spec.py, you need to prepare input files with command
 
     $ python run_etc.py @run_etc.defaults --MR_MODE=yes --EXP_TIME=450 --OUTFILE_SNC=out/etc-t450-mr.dat --OUTFILE_SNL=-
 
-You are now ready to generate simulated spectra.  The input spectrum is given by the `MAG_FILE` and may be either a file (with columns of wavelength and AB magnitude) or a floating point number (the AB magnitude of a flat-spectrum source).  The simulator will add appropriate noise, taking into account the number of integrations requested.  Run the gen_sim_spec.py like this:
+You are now ready to generate simulated spectra.  The input spectrum is given by the `MAG_FILE` and may be either a file (with columns of wavelength and AB magnitude) or a floating point number (the AB magnitude of a flat-spectrum source). The simulator will add appropriate noise, taking into account the number of integrations requested (see cautions in the previous section).  Run the gen_sim_spec.py like this:
 
     $ python gen_sim_spec.py --etcFile=out/etc-t450-lr.dat