Data Quality Reports for Session: 119877 User: mjensen Completed: 05/31/2009


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D060921.9NIM/TSI/M1 - Shadowband MisalignmentnimtsicldmaskM1.a1, nimtsimovieM1.a1, nimtsiskyimageM1.a1
D080304.2NIM/MET/M1 - ORG Data IncorrectnimmetM1.b1
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 : D060921.9
Start DateStart TimeEnd DateEnd Time
03/20/2006182009/29/20060945
Subject:
NIM/TSI/M1 - Shadowband Misalignment
DataStreams:nimtsicldmaskM1.a1, nimtsimovieM1.a1, nimtsiskyimageM1.a1
Description:
From installation, the shadowband was positioned south at solar noon until the vernal 
equinox when it began to migrate counter-clockwise until reaching east 37 days later on 4/26 
(about 9 days before mid-spring). The shadowband at solar noon continued to migrate until 
reaching its most northerly position (~15 deg) on the summer solstice (if everything was 
perfectly aligned, it probably would have been pointed north on this day). It then began 
to migrate clockwise and reached east again 56 days later on 8/16 (about 14 days after 
mid-summer). As expected, the shadowband reached its most southerly position on the 
autumnal equinox but was about 10 deg off of being due south. 

With the apparent alignment problem, I don't understand why the shadowband was mostly 
blocking the sun. When I started noticing this offset in May, I chose to leave it alone 
because I felt that adjusting the shadowband to where I thought it should be would cause it to 
not block the sun at either sunrise or sunset. 

The alignment was corrected on 9/29 (6 days after the day of the autumnal equinox).
Measurements:nimtsiskyimageM1.a1:
  • JPG data stream - documentation not supported(JPEG data stream - documentation not yet available)

nimtsicldmaskM1.a1:
  • PNG data stream - documentation not supported(png)

nimtsimovieM1.a1:
  • (MPEG data stream - documentation not yet available)


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DQRID : D080304.2
Start DateStart TimeEnd DateEnd Time
07/24/2006080007/24/20060900
Subject:
NIM/MET/M1 - ORG Data Incorrect
DataStreams:nimmetM1.b1
Description:
The ORG measured around 9cm of rain in a short period while other co-located sensors 
measured no precip.

Use the Present Weather Detector data instead or set the ORG rainfall to 0mm during this 
time period.
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 : 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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