Pahse Shift as a Function of Height

Hi,

In the attached file "Signal" I have three (3) columns of signals. The first column is height, second column and the third column are the two signals.

Please how can I calculate the Phase Shift between signal one (second column) and signal two (third column)as a function of height?.

The dt is 0.02 km. the data ranges from 20 to 40 km.

[dpb]

Don't see anything that looks like a phase shift in those signals; maybe there's a frequency difference between the two but hard to make much of the one that seems to have other stuff going on...

Try

figure
plot(signal)    % all as are
figure
plot(signal.*[1 -1 1])  % flip (:,2)

which is essentially saying there's a 180-deg phase shift.

The height variable is just a linear trend; don't see there's anything to be done with it presuming both were measured at the same height at the same time you have no way to separate anything about what its effect may have been.

Answer 1

[dpb]

Well, if you already have a phase shift, that's something else entirely...carrying on from above

phasedata=importdata('Schmidt_Fluctuation1_1.txt');
plot(phasedata,linspace(min(signal(:,1)),max(signal(:,1)),size(phasedata,1)))
xlim([-6 6])
legend("1&2","1&3","2&3")

yields

which presumes the data are in the order of min:max in the second array; otherwise reverse the y vector.

[TTA]

Thank you very much for your answer. But please my problem is to reproduce the phase shift plot as attached from the data.

[dpb]

Well, your data doesn't represent the same data as does the plot...nothing can do about that.

>> [min(phasedata);max(phasedata)]
ans =
   -2.5210   -2.1509   -2.8808
    4.1634    2.7267    3.2018
>> 

What else is to be made of that?

[TTA]

Ok thank you very much for your time

[dpb]

Unless there's more to what is in the file than just what those numbers are, I don't see what else there is that could be done with them.

What, specifically, are the data; how were they taken and what are we talking about some phase shift from? There has to be a reference for there to be a shift...there's no reference here that I can see.

[TTA]

Thank you very much for your williness to help. I really appreciate this.

Pls let me explain.

The phase shift I attached was derived, calculated or estimated from the text data file I attached. This was done picking combinations of signal 1 &2, 1&3, and 2&3 to derived the phase shifts I attached.

My problem is getting this phase shifts

[dpb]

Well, I'd have to see something about how those were "derived, calculated or estimated" from just those three traces to have a klew. Is there a reference paper from whence all these came that 'splains that somehow?

Otherwise, without some context for what the data are, how they were taken and what represent, seems hopeless to me.

[dpb]

[Toyese Answer moved to comment -- dpb]

here is a ref

https://doi.org/10.1002/2015JD024135

[dpb]

Very interesting paper! Just skimmed it, but from Section 6, Data Processing, one has the following overview of what they did...

"The temperature amplitude T, vertical wavelength λz, and phase Φ are obtained from a wavelet analysis for each single profile between 20 km and 40 km, whereas the dominant wave in each profile is determined at the power spectrum maximum at each altitude. The results are vertical profiles of T, λz (Figure 5b), and Φ, from which the phase differences between each pair are estimated (Figure 5c)."

So, there's a whole lot more data behind even getting those traces in that figure than just them...you'll have to go back and apply all those analyses step by step from the (undoubtedly mountains of) raw data to derive anything.

Those are all results, not starting points. Specifically, they go on to note "This follows the approach from Ern et al.[2011]"

Looks like you have a big job ahead of you to reproduce! :)

[dpb]

It looks like a fair amount of digging into the guts will be needed to figure out precisely how they did the phase shift...skimming the reference paper I didn't see any specific discussion on that portion...as noted earlier, it certainly isn't clear to me it's just some straightforward manipulation of those traces only...

But, that's research! :) Enjoy! Should be an enlightening area of study.

[TTA]

Hi,

I sincerely appreciate your effort.

Its not clear to me too thats why I asked.

I'll continue to try and hope I will get the problem solved soon.

Thanks so much for your time.

Tunde

[Ayush singhal]

@dpb

Hello is it possible to calculate the shift in the stripe pattern.

Any lead would be helpful.