Re: spectral Analysis

Hi Paul,

when you do a spectral analysis the lowest frequency you can resolve is 1/N
if N is the length of your time series. The highest frequency is 0.5/10mins
in your case, so half a cycle in 10 minutes. Or in general half a cycle in
the time interval. The frequency units will be 1cycle/time unit so in your
case cycles/10min. To get to cycles/min divide the frequency vector by 10.

It helps if you know certain signals in your data and what frequency they
should be at. That's a good sanity check when computing spectra to make
sure the frequency units are correct.

Hope this helps,
Maria


On Fri, Jul 18, 2014 at 3:58 AM, Steeven Paul Yerraguntla <
steevenpaul@gmail.com> wrote:

> Dear NCL users,
> I have plotted spectral variance to my data using Data
> Analysis examples in the NCL website. The data i have used is of 10 min
> interval and my doubt is that whether spectral frequency would be
> cycles/min or cycles/10min. If it is not cycles/min then how can i get
> the spectral Frequency in cycles/min. Hope i will get the answer soon.
> Thanks in advance.
>
> regards,
> Paul.
>
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Received on Fri Jul 18 05:26:04 2014