Improved doc in config file for sn_min and spectral_sn_min

CHANGELOG.md

@@ -11,6 +11,10 @@ Copyright (c) 2011-2024 Claudio Satriano <satriano@ipgp.fr>
 - Stacked spectra: color spectral curves according to the weighting function
 - Spectral plots: show information on the reason why a fit failed
 
+### Config file
+
+- Improved documentation for the `sn_min` and `spectral_sn_min` parameters
+
 ### Bugfixes
 
 - Fix for rejected spectra still being plotted in the stacked spectra plot

sourcespec/config_files/configspec.conf

@@ -234,6 +234,11 @@ save_spectra = boolean(default=False)
 rmsmin = float(min=0, default=0)
 
 # Time domain S/N ratio min
+# Note: in many cases, especially for small earthquakes recorded at broadband
+# sensors, it is better to leave this parameter to 0 (or 1) and use the
+# spectral S/N ratio instead (see "spectral_sn_min" below). This beacause time
+# domain S/N ratio can be close to 1 due to strong microseismic noise.
+# Band-limited noise is naturally handled by the spectral S/N ratio.
 sn_min = float(min=0, default=0)
 
 # Clipping detection algorithm
@@ -282,6 +287,8 @@ gap_max = float(min=0, default=None)
 overlap_max = float(min=0, default=None)
 
 # Minimum average spectral S/N ratio, below which a spectrum will be skipped
+# This parameter should be preferred to the time domain S/N ratio
+# ("sn_min", above) since it better handles band-limited noise.
 spectral_sn_min = float(min=0, default=0)
 # Frequency range (Hz) to compute the average spectral S/N ratio
 # (comment out or use None to indicate the whole frequency range)