[f] added attenuations and extinction coefficients

FHSTP/prep.py

@@ -543,6 +543,18 @@ def prep() -> None:
     _log('Calculated difference levels PDIFF instantaneous values derivating of daily means of dry periods')
     
     
+    # calculate attenuation of transmitted and received signal strengths per transmission
+    df_link['ATTENUATION'] = df_link['REMOTERXLEVEL'] - df_link['TXLEVEL']
+    _log('Calculated attenuation per transmission')
+    
+    # calculate extinction coefficients for links based on attenuation and lengths of the links based on beer-lambert law
+    # we can use the already computed Pinst values instead of the attenuation by simply multiplying the result with a constant of -1
+    # using PinstMean allows us to get the extinction coefficient (material properties) per link for dry periods (reference) of the day
+    # Coeff = -ln(10) * (Attenuation/PathLength) --> Coeff = ln(10) * (PinstMean/PathLength)
+    df_link['EXTINCTIONCOEFF'] = np.log(10) * (df_link['PINSTMEAN'] / df_link['LENGTH'])
+    _log('Calculated extinction coefficients based on beer-lambert law')
+    
+    
     # rename and reorder columns to aid RAINLINK format
     name_cols = {
         'LINKID' : 'ID',
@@ -554,6 +566,8 @@ def prep() -> None:
         'PINSTMEAN' : 'PinstMean',
         'PDIFF' : 'Pdiff',
         'TXLEVEL' : 'TxLevel',
+        'ATTENUATION' : 'Attenuation',
+        'EXTINCTIONCOEFFICIENT' : 'ExtinctionCoeff',
         'SPEED' : 'Speed',
         'CURRRXBITRATE' : 'RxBitrate',
         'CURRTXBITRATE' : 'TxBitrate',