Data Quality Reports for Session: 101026 User: perez Completed: 08/09/2006


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D030730.1TWP/GNDRAD/C2 - IRT problemtwpgndrad60sC2.b1
D041015.3TWP/GNDRAD/C2 - incorrect IRT calibrationtwpgndrad60sC2.b1
D050504.2TWP/GNDRAD/C2 - IRT connectortwpgndrad60sC2.b1
D050815.1TWP/GNDRAD/C2 - IRT power supply failedtwpgndradC2.00, twpgndrad60sC2.b1
D050926.6TWP/GNDRAD/C2 - Gndrad inverted for radiometertwpgndrad60sC2.b1
D060630.35TWP/GNDRAD/C2 - Reprocess: Longwave Calibration errortwpgndrad60sC2.b1


DQRID : D030730.1
Start DateStart TimeEnd DateEnd Time
07/12/2003210009/14/20031100
Subject:
TWP/GNDRAD/C2 - IRT problem
DataStreams:twpgndrad60sC2.b1
Description:
The GNDRAD IRT exhibited a positive bias compared to the PIR from 2100 to 0700 UTC each 
day. The problem was corrected by removing the signal cable, cleaning the contacts, and 
reconnecting the cable.
Measurements:twpgndrad60sC2.b1:
  • Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
  • Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
  • Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
  • Effective Surface (Skin) Temperature(sfc_ir_temp)


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DQRID : D041015.3
Start DateStart TimeEnd DateEnd Time
07/05/2004050107/19/20040206
Subject:
TWP/GNDRAD/C2 - incorrect IRT calibration
DataStreams:twpgndrad60sC2.b1
Description:
When the GNDRAD data logger was upgraded, the calibration offset for the IRT was initially 
incorrect.
Measurements:twpgndrad60sC2.b1:
  • Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
  • Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
  • Effective Surface (Skin) Temperature(sfc_ir_temp)


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DQRID : D050504.2
Start DateStart TimeEnd DateEnd Time
03/27/2005233004/03/20050240
Subject:
TWP/GNDRAD/C2 - IRT connector
DataStreams:twpgndrad60sC2.b1
Description:
The IRT had a problem with the connector of either the signal or power cable which 
produced an output of 0 volts equivalent to a measurement of 223K. The problem was corrected 
when the connectors were cleaned and tightened.
Measurements:twpgndrad60sC2.b1:
  • Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
  • Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
  • Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
  • Effective Surface (Skin) Temperature(sfc_ir_temp)


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DQRID : D050815.1
Start DateStart TimeEnd DateEnd Time
08/11/2005164808/16/20052230
Subject:
TWP/GNDRAD/C2 - IRT power supply failed
DataStreams:twpgndradC2.00, twpgndrad60sC2.b1
Description:
The IRT output dropped to its minimum output of 223 K (0 volts).  It was determined the 24 
V DC converter had failed.  The converter was replaced on 16 August and the instrument 
began reporting normally again.  The IRT data are unusable during the five day period when 
the DC converter was faulty.

The GNDRAD (down-looking) IRT is used primarily for surface temperature.  The PIR can be 
used for this purpose by inverting the IR flux equation, Flux = sigma*temperature^4 where 
sigma = 5.67x10-8 W/m^2K^4.  But, unlike the IRT, the PIR measurement is strongly 
effected by the air temperature in addition to the surface temperature.  At night, when the air 
temperature approaches the surface temperature, the PIR provides a good estimate of the 
surface temperature.  During the day, however, the PIR tends to underestimate the ground 
temperature,  particularly on sunny days.  The magnitude of the underestimate can be 
estimated by evaluating periods when both instruments are operating but is typically on the 
order of 5-10C.
Measurements:twpgndradC2.00:
  • Raw data stream - documentation not supported(Raw data stream - documentation not supported)

twpgndrad60sC2.b1:
  • IRT1 maximum(irt1_max)
  • IRT1 mean(irt1_mean)
  • IRT1 standard deviation(irt1_sd)
  • IRT1 minimum(irt1_min)


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DQRID : D050926.6
Start DateStart TimeEnd DateEnd Time
09/17/2005015209/23/20050115
Subject:
TWP/GNDRAD/C2 - Gndrad inverted for radiometer
DataStreams:twpgndrad60sC2.b1
Description:
Gndrad instruments PIR and PSP inverted for replacement instrument
installation and comparison
Measurements:twpgndrad60sC2.b1:
  • Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer(up_short_hemisp)
  • PSP1 unshaded maximum(psp1_max)
  • Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
  • Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
    Maxima(up_long_hemisp_max)
  • PIR1 unshaded minimum(pir1_min)
  • Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
    Maxima(up_short_hemisp_max)
  • PIR1 unshaded mean(pir1_mean)
  • PSP1 unshaded standard deviation(psp1_sd)
  • Effective Surface (Skin) Temperature(sfc_ir_temp)
  • PIR1 unshaded standard deviation(pir1_sd)
  • Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)
  • Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
  • PIR1 unshaded maximum(pir1_max)
  • Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
    Standard Deviation(up_short_hemisp_std)
  • PSP1 unshaded minimum(psp1_min)
  • Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
    Minima(up_short_hemisp_min)
  • Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
  • Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
    Standard Deviation(up_long_hemisp_std)
  • Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
    Minima(up_long_hemisp_min)
  • PSP1 unshaded mean(psp1_mean)


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DQRID : D060630.35
Start DateStart TimeEnd DateEnd Time
07/05/2004220212/21/20052149
Subject:
TWP/GNDRAD/C2 - Reprocess: Longwave Calibration error
DataStreams:twpgndrad60sC2.b1
Description:
Modified pyrgeometer calibration procedures were implemented beginning in December 2003.  
These modified procedures introduced a calibration bias in the longwave data.  The 
previous procedures were re-implemented at all sites between December 2005 and February 2006 to 
restore proper calibrations.                                                             
                The data collected while the incorrect procedures were in place are 
being reprocessing to remove the calibration bias.  Note, this also affected standard 
deviation, maximum and minimum data fields.
Measurements:twpgndrad60sC2.b1:
  • Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)


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