Timeline for How to remove the frequency noises in a Fourier Transformation on an experimental data？
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 5, 2016 at 12:04 | comment | added | user14634 | @ JasonB, The bandwidth in time domain is about 400fs. According to the transform limited condition, the frequency bandwidth should be 0.44/400=0.0011 (1/fs). The width of the above figure is about 0.2 (1/fs). too big? | |
| Apr 5, 2016 at 9:58 | comment | added | Jason B. | Right, but if the window were any wider in time, it would be narrower in frequency and then you still have two peaks. See what happens when you change the value in the gaussian window from 25.0 to 100.0, you still get two peaks. | |
| Apr 5, 2016 at 9:57 | comment | added | user14634 | @ JasonB, I agree it is necessary to add a window, but I think it is better to add a large window, so as to keep more original data, under the condition that we can obtain a single peak. | |
| Apr 5, 2016 at 9:56 | comment | added | Jason B. | @user14634 then, in my opinion, your instrument will not allow you to resolve that peak with good resolution. I don't see how you can fudge the data to give what you seek | |
| Apr 5, 2016 at 9:53 | comment | added | user14634 | @ JasonB, Yes, the frequency center should be 0.2124. | |
| Apr 5, 2016 at 9:31 | comment | added | Jason B. | @user14634 and is that center frequency in the center of the two peaks you get above? | |
| Apr 5, 2016 at 9:30 | comment | added | user14634 | @ JasonB, I have already known the center frequency, since I can measure the center frequency in experiment by using other devices, e.g., a spectrometer. What I most want to obtain from this time-domain interference data, is the bandwidth, i.e., the time-domain width and the frequency-domain width (after Fourier transform). | |
| Apr 5, 2016 at 6:59 | comment | added | Jason B. | @user14634 - I think that is specifically not possible. That is, with this data, it is not possible to extract a single frequency and bandwidth. In your post you said you wanted a single peak, and the only way to do that with this data, to my knowledge, is to apply the window and broaden the two peaks such that they merge. | |
| Apr 5, 2016 at 4:25 | comment | added | user14634 | Thanks a lot again for your kind help. Your method of adding a window really suppressed the multi-peak. But, this window is too small and raw data was partially changed. The bandwidth information is the most important information for me. Is it possible to design a bigger window such that the raw data is changed as few as possible? | |
| Apr 4, 2016 at 10:29 | history | answered | Jason B. | CC BY-SA 3.0 |