Input data: hi-res cube with t_first=1998.06.18_15:36:59.0_UT, binned 2x2. The unbinned cubes are on tape MDI_3. 512 frames.
In the directory Freq_filt is the results of using a filter of fwhm=1mhz and center frequency=3mhz and distance range of 4.692 to 5.372. The rms of the central 33:96,33:96 of the mean signal is 0.55min.
In the directory Phase_filt is a result of a phase speed filtering with nu/l=13.98 and width 1.3 for the same distance range. The rms for the central region for the mean signal is 0.11min., or a factor of five smaller.
In some of the other directories Phase_filtn, n=2-4, are some other tests of phase speed filters with different widths. The column "rms after fit" refers to the residuals of a parabolic fit to the central 33:96,33:96 of the mean signal.
| Directory | filter width(microhz) | rms noise (min) | distance range (deg) | rms after fit | exec. time(min) |
|---|---|---|---|---|---|
| Phase_filt3 | 1.0 | 0.118 | 4.692-5.372 | 0.102 | 267 |
| Phase_filt | 1.3 | 0.108 | 4.692-5.372 | 0.092 | |
| Phase_filt2 | 2.6 | 0.099 | 4.692-5.372 | 0.079 | 268 |
| Phase_filt4 | 5.2 | 0.121 | 4.692-5.372 | 0.098 | 243 |
| Phase_filt5 | 5.2 | 0.115 | 4.352-5.712 | 0.093 | 352 |
| Phase_filt6 | 2.6 | 0.132 | 4.896-5.168 | 0.114 | 200 |
| Phase_filt7 | 1.3 | 0.148 | 4.896-5.168 | 0.136 | 200 |
| Phase_filt8 | 1.0 | 0.156 | 4.896-5.168 | 0.145 | 215 |