Data Quality Reports for Session: 117586 User: michel1cho Completed: 02/17/2009


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D080304.3NIM/MET/M1 - ORG Data Underestimated PrecipitationnimmetM1.b1
D080428.7NIM/MET/M1 - Reprocess: ORG Data has very small rainrate valuesnimmetM1.b1
D081022.11NIM/MET/M1 - Wind Speed data contain offset due to induced voltagenimmetM1.b1


DQRID : D080304.3
Start DateStart TimeEnd DateEnd Time
01/06/2006000001/06/20072359
Subject:
NIM/MET/M1 - ORG Data Underestimated Precipitation
DataStreams:nimmetM1.b1
Description:
The ORG underestimated precipitation by about 38% during the entire NIM deployment.  No 
troubleshooting technique or replacement of gage was successful in correcting the problem.
Measurements:nimmetM1.b1:
  • Precipitation rate mean(precip_rate_mean)
  • ORG carrier mean(org_carrier_mean)
  • Precipitation rate maximum(precip_rate_max)
  • Precipitation rate minimum(precip_rate_min)
  • Precipitation rate standard deviation(precip_rate_sd)


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DQRID : D080428.7
Start DateStart TimeEnd DateEnd Time
01/06/2006000001/07/20072359
Subject:
NIM/MET/M1 - Reprocess: ORG Data has very small rainrate values
DataStreams:nimmetM1.b1
Description:
The ORG data is collected via analog signal and not digital.  Therefore, we
   continuously collect data even when no rain is occurring.  We also capture
   small events such as leaves, large bugs, dust, etc blowing through the
   measurement path.  Because this discrete event occurs quickly the value is
   usually captured for 1 or 2 seconds.  This value is then averaged to the
   minute producing rainrate on the order of .009 mm/hr or less.  These values
   are not indicative of rain and should be removed from the record or summing
   over long periods can bias the climate record.  We are reprocessing the data
   to remove these small values and are adjusting the collection program to
   remove them before ingest.
Measurements:nimmetM1.b1:
  • Precipitation rate mean(precip_rate_mean)
  • Precipitation rate maximum(precip_rate_max)
  • Precipitation rate minimum(precip_rate_min)
  • Precipitation rate standard deviation(precip_rate_sd)


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DQRID : D081022.11
Start DateStart TimeEnd DateEnd Time
01/06/2006000001/07/20072359
Subject:
NIM/MET/M1 - Wind Speed data contain offset due to induced voltage
DataStreams:nimmetM1.b1
Description:
The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.
Measurements:nimmetM1.b1:
  • Wind speed arithmetic standard deviation(wind_spd_arith_sd)
  • Wind speed arithmetic maximum(wind_spd_arith_max)
  • Vector-averaged Wind Speed(wind_spd_vec_avg)
  • Wind speed arithmetic average(wind_spd_arith_avg)
  • Wind speed arithmetic minimum(wind_spd_arith_min)


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