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how to convert wavelength domain to frequency domain plot?
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izzati
May 6, 2014, 3:39:12 AM5/6/14
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i have plot my signal in wavelength domain(intensity vs wavelength). i want to view my output in time domain(intensity vs time). i know that I have to convert first the wavelength domain to frequency domain. so, how am I going to do that? what is the coding involved?
TideMan
May 6, 2014, 4:40:25 AM5/6/14
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On Tuesday, May 6, 2014 7:39:12 PM UTC+12, izzati wrote:
> i have plot my signal in wavelength domain(intensity vs wavelength). i want to view my output in time domain (intensity vs time). i know that I have to convert first the wavelength domain to frequency domain. so, how am I going to do that? what is the coding involved?
For flowing water, this is done using Taylor's hypothesis of frozen turbulence, which says that you can convert from wave number, k, to frequency, w, using the freestream velocity.
Thus:
w=U*k
where U is the freestream velocity.
G I Taylor developed this hypothesis back in the 1920s when he had measurements of flow along a flume and he wanted to convert those to a time record at a point.
I guess if your signal is sound, you would use the speed of sound as U.
For ocean waves, the relationship is much more complicated:
w^2=gk tanh(kh)
> i have plot my signal in wavelength domain(intensity vs wavelength). i want to view my output in time domain (intensity vs time). i know that I have to convert first the wavelength domain to frequency domain. so, how am I going to do that? what is the coding involved?
For flowing water, this is done using Taylor's hypothesis of frozen turbulence, which says that you can convert from wave number, k, to frequency, w, using the freestream velocity.
Thus:
w=U*k
where U is the freestream velocity.
G I Taylor developed this hypothesis back in the 1920s when he had measurements of flow along a flume and he wanted to convert those to a time record at a point.
I guess if your signal is sound, you would use the speed of sound as U.
For ocean waves, the relationship is much more complicated:
w^2=gk tanh(kh)
izzati
May 6, 2014, 12:24:13 PM5/6/14
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thank you for your reply. now i'm doing on light propagation. as i want to transform from graph of intensity vs wavelength to intensity vs freq. later on, intensity vs time. The equation involved is
freq=speed of light/wavelength
can I just applied this equation to obtain the graph? as I look up at the help menu, there is function of fft and ifft involved.
freq=speed of light/wavelength
can I just applied this equation to obtain the graph? as I look up at the help menu, there is function of fft and ifft involved.
radhika...@gmail.com
Jun 30, 2016, 1:57:50 AM6/30/16
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On Tuesday, May 6, 2014 at 1:09:12 PM UTC+5:30, izzati wrote:
> i have plot my signal in wavelength domain(intensity vs wavelength). i want to view my output in time domain(intensity vs time). i know that I have to convert first the wavelength domain to frequency domain. so, how am I going to do that? what is the coding involved?
Hi
> i have plot my signal in wavelength domain(intensity vs wavelength). i want to view my output in time domain(intensity vs time). i know that I have to convert first the wavelength domain to frequency domain. so, how am I going to do that? what is the coding involved?
even i am doing work on light propagation .also i too have the same problem
i have plot my signal in wavelength domain(intensity vs wavelength). i want to view my output in time domain(intensity vs time). i know that I have to convert first the wavelength domain to frequency domain. so, how am I going to do that?did you get how to do that
Nasser M. Abbasi
Jun 30, 2016, 3:07:43 AM6/30/16
to
On 6/30/2016 12:57 AM, radhika...@gmail.com wrote:
>i want to view my output in time domain(intensity vs time). i know that I have to convert
>first the wavelength domain to frequency domain. so, how am I going to do that?did you get how to do that
>
normally fft is used for these things. But if you special and more advanced
>i want to view my output in time domain(intensity vs time). i know that I have to convert
>first the wavelength domain to frequency domain. so, how am I going to do that?did you get how to do that
>
DSP questions, you can ask it in comp.dsp.
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