# Gauss Parameter on Water Level Deconvolution
**URL:** https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261
**Category:** Related: rf
**Created:** [June 17, 2021, 2:48pm UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261 "2021-06-17T14:48:28Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Indra\_Siregar](https://discourse.obspy.org/u/Indra_Siregar)
#### Post date: [June 17, 2021, 2:48pm UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/1 "2021-06-17T14:48:28Z")
Dear all,
Let me ask about the Gaussian parameter on the water-level method. How is the relationship between the gauss parameter and the alpha value? I still don’t understand, because generally, this method uses alpha values, such as alpha=2.5, 3.5, etc. Thank you.
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### Author:  [@trichter](https://discourse.obspy.org/u/trichter)
#### Post date: [June 21, 2021, 8:11am UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/2 "2021-06-21T08:11:25Z")
Hi,
I know of a Gaussian parameter which defines the width of a Gaussian low pass filter in frequency domain. Probably there is more than one definition for Gaussian parameter and alpha. Do you refer to a specific implementation or formula?
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### Author:  [@Indra\_Siregar](https://discourse.obspy.org/u/Indra_Siregar)
#### Post date: [June 21, 2021, 9:01am UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/3 "2021-06-21T09:01:30Z")
yes, I mean if I input gauss = 0.5, what is the value in alpha? The point is how to convert the gauss value into alpha value, sir. Thank you.
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### Author:  [@trichter](https://discourse.obspy.org/u/trichter)
#### Post date: [June 21, 2021, 9:27am UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/4 "2021-06-21T09:27:01Z")
I have no clue. Where do you input gauss? What is the definition of alpha?
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### Author:  [@Indra\_Siregar](https://discourse.obspy.org/u/Indra_Siregar)
#### Post date: [June 21, 2021, 10:39am UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/5 "2021-06-21T10:39:02Z")
I input the gauss on water level deconvolution.
Alpha is the width factor for the Gaussian filter. So, the alpha will affect the frequency content.
This is the formula of Gaussian filter:
G(ω)=exp((-ω^2)/(4 a^2 )), with a is alpha
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### Author:  [@trichter](https://discourse.obspy.org/u/trichter)
#### Post date: [June 21, 2021, 10:59am UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/6 "2021-06-21T10:59:11Z")
Thanks for the explanation.
In the docs the parameter is described with
**gauss** – Gauss parameter (standard deviation) of the Gaussian Low-pass filter, corresponds to cut-off frequency in Hz for a response value of exp(0.5)=0.607.
(Actually a minus is missing, it should be exp(-0.5)=0.607)
The frequency response is given by
```python
exp(-0.5 * (f/f0) ** 2)
```
with f0 being the gauss parameter.
With ω = 2πf follows
f0 = √2 a / (2π) = 0.225 a
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### Author:  [@Indra\_Siregar](https://discourse.obspy.org/u/Indra_Siregar)
#### Post date: [June 21, 2021, 11:26am UTC](https://discourse.obspy.org/t/gauss-parameter-on-water-level-deconvolution/1261/7 "2021-06-21T11:26:11Z")
Wow, that’s very clear. Thank you for your help. I greatly appreciate it.