Difference between revisions of "CDC algo tuning"
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|+ High and low thresholds found using upsampled data, with interpolation | |+ High and low thresholds found using upsampled data, with interpolation | ||
− | |[[Image:cdc_run_31942_track127a_np16_thr_5_4_1.png|thumb| | + | |[[Image:cdc_run_31942_track127a_np16_thr_5_4_1.png|thumb|x200px|Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000]] |
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|+ Did not search again for hit threshold, used sample 9, High and low thresholds found using upsampled data, with interpolation | |+ Did not search again for hit threshold, used sample 9, High and low thresholds found using upsampled data, with interpolation | ||
− | |[[Image:cdc_run_31942_track127b_np16_thr_5_4_1.png|thumb| | + | |[[Image:cdc_run_31942_track127b_np16_thr_5_4_1.png|thumb|x200px|Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000]] |
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Revision as of 20:44, 5 December 2013
Using prototype data from CDC_50_50 (run 31942) with offline analysis
50/50 Ar/CO2 and cosmics, 2100V, prototype horizontal
Original code, many samples upsampled
- Event pedestal is mean of 100 samples ending at trigger time
- Find hit threshold crossing
- Step back <pedlead> points to find new local pedestal
- Search forward to find high threshold crossing
- Search backward to find low threshold crossing
- Project through both thresholds to find pedestal crossing time
Trying out ideas for simplification
Ideas
- Check whether interpolating threshold xings makes any difference - no, not if extrapolating through thresholds to pedestal.
- Use the 3rd sample (or mean of 3rd & 4th samples) before hit threshold as local pedestal
- Try reverting to one threshold crossing instead of the extrapolation - only slight increase to res width
- Try something easier for event pedestal - mean of 4 samples immediately before trigger - this might be an improvement, probably because the pedestal is closer in time to the hits
- Event pedestal is mean of 4 samples ending at trigger time
Fewer samples upsampled
- Event pedestal is mean of 100 samples ending at trigger time
- Find hit threshold crossing
- Upsample region around threshold crossing, with threshold crossing sample in set position (10th sample)
- Search again for hit threshold in small region of upsampled data
- Step back <pedlead> points to find new pedestal
- Search forward to find high threshold crossing
- Search backward to find low threshold crossing
- Project through both thresholds to find pedestal crossing time