Difference between revisions of "CDC algo tuning"

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{| border="0" cellpadding="2"  
 
{| border="0" cellpadding="2"  
 
|+ All thresholds found using upsampled data, with interpolation
 
|+ All thresholds found using upsampled data, with interpolation
|[[Image:cdc_run_31942_track127c_np16.png|thumb|x150px|Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000]]
+
|[[Image:cdc_run_31942_track127c_np16.png|thumb|x200px|Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000]]
|[[Image:cdc_run_31942_track127c_np16_thr_5_4_2.png|thumb|x150px|Thresholds 5-4-2 pedlead 16 tz 7 tfix 1000]]
+
|[[Image:cdc_run_31942_track127c_np16_thr_5_4_2.png|thumb|x200px|Thresholds 5-4-2 pedlead 16 tz 7 tfix 1000]]
|[[Image:cdc_run_31942_track127c_np16_thr_5_4_3.png|thumb|x150px|Thresholds 5-4-3 pedlead 16 tz 7 tfix 1000]]
+
|[[Image:cdc_run_31942_track127c_np16_thr_5_4_3.png|thumb|x200px|Thresholds 5-4-3 pedlead 16 tz 7 tfix 1000]]
 
|}
 
|}
  
 +
{| border="0" cellpadding="2"
 +
|+ All thresholds found using upsampled data, without interpolation at the high and low threshold xings
 +
|[[Image:cdc_run_31942_track127d_np16_thr_5_4_1.png|thumb|x200px|Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000]]
 +
|}
  
 
<h4>Fewer samples upsampled</h4>
 
<h4>Fewer samples upsampled</h4>

Revision as of 18:01, 4 December 2013

Using prototype data from CDC_50_50 (run 31924) with offline analysis

50/50 Ar/CO2 and cosmics, 2100V, prototype horizontal

Original code, many samples upsampled

  1. Event pedestal is mean of 100 samples ending at trigger time
  2. Find hit threshold crossing
  3. Step back <pedlead> points to find new pedestal
  4. Search forward to find high threshold crossing
  5. Search backward to find low threshold crossing
  6. Project through both thresholds to find pedestal crossing time
All thresholds found using upsampled data, with interpolation
Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000
Thresholds 5-4-2 pedlead 16 tz 7 tfix 1000
Thresholds 5-4-3 pedlead 16 tz 7 tfix 1000
All thresholds found using upsampled data, without interpolation at the high and low threshold xings
Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000

Fewer samples upsampled

  1. Event pedestal is mean of 100 samples ending at trigger time
  2. Find hit threshold crossing
  3. Upsample region around threshold crossing, with threshold crossing sample in set position
  4. Step back <pedlead> points to find new pedestal
  5. Search forward to find high threshold crossing
  6. Search backward to find low threshold crossing
  7. Project through both thresholds to find pedestal crossing time
High and low thresholds found using upsampled data, with interpolation
Thresholds 5-4-1 pedlead 16 tz 7 tfix 1000


Ideas

  1. Check whether interpolating threshold xings makes any difference
  2. Use the 3rd sample (or mean of 3rd & 4th samples) before hit threshold as local pedestal
  3. Try reverting to one threshold crossing instead of the extrapolation
  4. Try something easier for event pedestal - mean of 4 samples immediately before trigger