Attached plot, data and code for a high resolution (0.2 mHz) PSD around the violin modes. Here's how it was computed:
- read CAL-DELTAL_EXTERNAL_DQ for one lock durign the weekend (see 43661, data from 1219293018 to 1219305618)
- decimate to 4096 Hz
- heterodyne with a complex sinusoid at 507 Hz
- decimate the result at 32 Hz
- compute the PSD and upshift the frequency bins by 507 Hz
Additionally, I adapted some code from the C.Ri.Me. lab code library to identify peaks and measure the frequencies (code in the attached notebook). Here's a list of the main peak identified in this way and a plot
Freq. [Hz] SNR 501.5549 216 501.6304 22387449 501.6934 2208 501.7563 1016510 502.7843 5148 502.9086 3800670 503.0852 62183 503.1976 9143441 503.6788 1360642 503.7344 8771479 504.1450 10496208 504.1786 3180409 504.6066 451 504.8855 63210 504.8906 195549 504.9527 3884 505.0795 15773030 507.3577 1366 507.4948 40605 508.8452 2856 508.9412 5231498 510.7134 975575 511.1883 210 511.2993 327 513.5110 265289 516.6803 536 516.6822 59
The attached script can be used to generate the output above from any GPS times.
Syntax:
python violin_psd.py start_gps end_gps [resolution]
where the optional parameter is the frequency resolution in Hz (default to 2e-4 Hz).
The output are four files:
violin_modes_0.2mHz_resolution_*.png plot of the PSD
violin_modes_0.2mHz_resolution_*.txt full data for the PSD (in a range centered at 507 Hz)
violin_modes_0.2mHz_resolution_peaks_*.png same lot aa above, but with the identified peaks highlighted
violin_modes_0.2mHz_resolution_peaks_*.txt list of the identified peaks, same as what is printed on screen
A new PSD from the lock that is going on right now.
Freq [Hz] SNR
501.5550 459101
501.6305 61232190
501.6937 455339
501.7564 867059
502.7844 103124
502.9087 783689
503.0851 4840352
503.1974 2751967
503.6788 69546
503.7344 23972
504.1449 127328
504.1784 1989882
504.6069 31477
504.7199 964331
504.8523 1286321
504.8907 472099
504.9520 417818
505.0795 610232
505.1885 962338
507.3616 2042637
508.8460 4356110
508.9411 155619
510.7133 601203
511.1812 5551906
513.4049 1859193
516.6799 11926450
516.7792 8724
