<p>The simplest method is the spectral ratio method where the frequency spectra at two different depth levels in the VSP are computed and divided i.e. the ratio of the spectra. IN theory the slope of this spectral ratio is related to the attenaution factor Q. However, this method is not very robust and the data needs careful preconditioning to remove reflections, multiples, conversions etc. There are many others methods that have been developed and are described in the literature e.g. Geophysics.</p>

CC BY-SA 4.0
2021-06-30T15:52:37.460Z
2021-06-30T15:52:37.460Z
Steve
<p>in seismic data processing there is a step of calculating the absorption represented By Q value which is Q factor , how we can estimate it from VSP ! 
thank you.</p>

CC BY-SA 4.0
2020-03-24T08:54:56.183Z
Do you have a paper or reference that your question is based on? As with all things to do with Q values, I bet there are 101+ ways of approximating the forward and inverse problems, so it'd be helpful to know exactly what case you are looking at.
Erik
CC BY-SA 4.0
2020-03-24T21:41:45.020Z
i need just one way that can help me to estimate the value of Q using VSP data and if there is a way without VSP you can tell me about it too , thank you !
Djabri Josef
CC BY-SA 4.0
2020-03-24T21:43:30.237Z
thank you @Universal_learner that paper was so helpful .
Djabri Josef
<geophysics><seismic>
Q factor estimation from VSP
Djabri Josef
# Q factor estimation from VSP

(Asked by: username_0 on 2020-03-23)

in seismic data processing there is a step of calculating the absorption represented By Q value which is Q factor , how we can estimate it from VSP !
thank you.

**Tags:** geophysics, seismic

> **Comments:**
> **username_1**: Do you have a paper or reference that your question is based on? As with all things to do with Q values, I bet there are 101+ ways of approximating the forward and inverse problems, so it'd be helpful to know exactly what case you are looking at.  
> **username_0**: i need just one way that can help me to estimate the value of Q using VSP data and if there is a way without VSP you can tell me about it too , thank you !  
> **username_0**: thank you @Universal_learner that paper was so helpful .  

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## 1 answers

### Answer by username_2 on 2021-06-30. Score: 1

The simplest method is the spectral ratio method where the frequency spectra at two different depth levels in the VSP are computed and divided i.e. the ratio of the spectra. IN theory the slope of this spectral ratio is related to the attenaution factor Q. However, this method is not very robust and the data needs careful preconditioning to remove reflections, multiples, conversions etc. There are many others methods that have been developed and are described in the literature e.g. Geophysics.


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