BesselBaseCoefficients

Return coefficients of normalized low pass Bessel filter (= gain at cut-off frequency 1 rad/s is decreased 3dB)

toHighestPowerOne

Transform filter to form with highest power of s equal 1

normalizationFactor

Compute correction factor of low pass filter such that amplitude at cut-off frequency is -3db (=10^(-3/20) = 0.70794...)

bandPassAlpha

Return alpha for band pass