Here is a small description of the sub-menus called :

0-mean: remove the continous componant of a signal (its average becomes NULL)

Band-Pass: Combination of both HIGH and LOW Pass in cascade, it creates a band-pass filter

*Example of band-pass [0.02 – 0.1] Hz 4*^{th}order

Low-Pass: Classical, but safe, value in filtering : the Butterworth filter of 2*n order (the order must be even)

*Example: Low-pass filter 4*^{th}order, 0.05 Hz

High-Pass: Butterworth filter of 2*n order, High-Pass

*High-pass 0.02 Hz 4*^{th}order

Farrer-12-6s: a combination of low-pass and rejectors, giving very steep slope near the cut-off frequency, for removing oceanic noise.

*Farrer filter 12-6s 4*^{th}order

10%-taper: the generalized Hanning window : a cosine on half a given period.

*Taper 10%*

Trend: For removing trend of a signal with a best fitted polynome of 1 order (it does not introduce dephasage)

*Before Trend order 1 filter**After Trend order 1 filter: the very long period trend is removed*

Polynomial-trend: removes trend of a signal with a best fitted polynome of n order (without dephasage)

*After
Trend order 3 filter: the very long period trend is better removed
than with order 1*

Remove-LTA (Long Time Average): for removing very long period oscillations in a signal (like a smooth high pass)

*Same as above, plus remove_LTA filter, this processing remove period with a cut-off period of 1000s**Modulus of transfer function of remove_LTA filter*

Natural integrator: the pure mathematical integration, like dividing the the spectrum by

*j**w*, but it works also in the time domain*Modulus of transfer function of trapezoidal integrator*

Natural derivator: the pure derivation operator (product by

*j**w*), in the time domain also, with the Z bilinear transform.*Modulus of transfer function of natural derivator*

Integrator Fc: an integrator with a cutt-off frequency, it avoids the amplification of the low frequencies to infinite.

*Modulus of transfer function of integrator with 1000s of corner period; notice the fall of modulus close to Nyquist frequency.*Rejector Fc: a stable and simple rejector of 2n order, for removing sharp rai of noise.

*Modulus of transfer function of rejector order 4 at 0.1 Hz*PolePedestal : this filter is the inverse of the rejector filter of 2n order, for amplifying sharp rais of signal.

*Pole on pedestal filter is the the inverse effect of a rejector : it amplifies a sharp frequency band.*Median filter: a non linear filter for removing stupid individual points (spikes) in a signal. This filter has a non linear response.

Of course, the transfer function cannot be calculated by injecting a Dirac as the input of the filter: It will be removed!

Compensator 1: a filter for compensating instrumental response with order one.

Compensator 2: a filter for compensating instrumental response with order two.*Example of compensator order 2 between 0.1 and 0.02 Hz. Despite of arbitray unit on the vertical scale (Fourier transform of a Dirac of arbitray unit convolved with the desired filter), the gain is exactly 1.0 toward the high frequency limit.*Init Signal : reload the unfiltered signal in the given window.