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: http://www.naic.edu/~phil/hardware/pdev/noise_08jul08/spectraVsADsig_08jul08.html
Дата изменения: Tue May 25 01:38:42 2010 Дата индексирования: Sun Sep 12 11:43:07 2010 Кодировка: Поисковые слова: п п п п п п п |
butterfly downshifts
used |
a/d rms |
Relative
power levels of spectra vs fftlen |
|||||
8192 | 4096 | 2048 | 1024 | 512 | |||
0 |
bandPass
shape |
80 |
3.6 |
7.1 |
3.6 |
7.1 |
3.6 |
1 |
9 downshifts then 0,1 |
30 |
.50 |
1 |
.5 |
1 |
.5 |
2 |
9
downshifts then 0,1 |
25 |
.35 |
.7 |
.35 |
.7 |
.35 |
3 |
9
downshifts then 0,1 |
20 |
.22 |
.44 |
.22 |
.44 |
.22 |
4 |
10
downshifts then 0,1 |
30 |
.5 |
.25 |
.5 |
.25 |
.5 |
5 |
9
downshifts then 0,1 |
15 |
.13 |
.25 |
.13 |
.25 |
.5 |
8192 |
4096 |
2048 |
1024 |
512 |
|
band
pass shape: These plots show the bandpass shape for the various beams and fftlengths. The bandpass with rms=80 is plotted as well as the bandpass with rms=30 counts. You can see that the spectra with rms=30 has more bumps in it than that with 80 counts. I wouldn't expect this to be the case.
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plot |
plot | plot | plot | plot |
Ratio
spectra/spectraRms80: The spectra from each test has been divided by the spectra with rms=80 to get rid of the bandpass shape.
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plot | plot | plot | plot | plot |
Ratio
spectra/spectraRms80 Blowup: The previous set of plots has been blown up about fftlen/4 and fftlen/2 to see the possible jumps.
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plot | plot | plot | plot | plot |