DQRID : D140221.8
Start DateStart TimeEnd DateEnd Time Data Quality Metric
05/03/2012000001/28/20140000Does not affect quality
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Subject:
SGP/RL/C1 - Reprocessing Notice (RID 1026)
DataStreams:sgprlprofmerge1turnC1.c0
Description:
See below for details of reprocessing that was completed on 20140822.  Original DQR 
category:3 (Yellow, Suspect ).

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Regions where photon counting rates exceed 20 MHz are 37.5 meters too high. Correct data 
by shifting down 37.5 meters.


Additional information:
The detection system in the RL uses Licel data recorders. These recorders provide 
simultaneous measurements of analog voltage and photon counts from the photo multiplier tubes. 
The analog signal has an inherent delay relative to the photon counting signal, which is 
corrected for in the rlprofmerge VAP. The delay parameter is determined through offline 
analysis by the instrument mentor, and then inputted into a configuration file that is used 
by the VAP.
During the effected period, the delay parameter for the narrow-field-of-view elastic 
channel was incorrect. As a result, the  analog signal leads the photon counting signal by 5 
range bins (5X7.5m = 37.5m). Photon counting rates that are outputted by the rlprofmerge 
VAP use the analog signals in regions where the photon counting rates exceed 20 MHz. So 
the counting rate data in these regions are (incorrectly) shifted downward by 37.5 m (i.e. 
-37.5m).
Suggestions: 
Measurements:sgprlprofmerge1turnC1.c0:
  • elastic_counts_high_glue_coef_offset
  • elastic_counts_high
  • elastic_counts_high_glue_coef_slope
  • height_high
  • electronic_background_elastic_analog_high
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