DQRs for Session: 107723 User:bmhCompleted: 09-12-2007

Data Quality Reports for Session: 107723 User: bmh Completed: 09/12/2007

TABLE OF CONTENTS

DQR ID	Subject	Data Streams Affected
D040421.3	NSA/SKYRAD/C1 - itermittant IRT bias	nsaskyrad60sC1.b1
D051202.1	NSA/SKYRAD/C1 - Reprocess: Incorrect datalogger program affecting PIR1 and PIR2 downwelling longwave	nsaskyrad20sC1.a0, nsaskyrad60sC1.b1
D060630.37	NSA/SKYRAD/C1 - Reprocess: Longwave Calibration error	nsaskyrad60sC1.b1

DQRID : D040421.3

Start Date	Start Time	End Date	End Time
03/28/2003	0200	06/21/2006	0215

Subject:	NSA/SKYRAD/C1 - itermittant IRT bias
DataStreams:	nsaskyrad60sC1.b1
Description:	A problem with the SKYRAD IRT that itermittantly produced a gradual increase in the sky temperature measurement then a sudden correction, as compared to AERI, appears to have been caused by a combination of a failing IR detector, a poor signal cable, a contaminated (with condensation or frost) mirror or lens, and low ambient temperatures. The positive bias was apparently not consistant in either frequency or duration but on days when the unusual behavior is observed, it usually occurred from about 00:00 to 06:00 local time. The instrument was repaired and recalibrated and the signal cable replaced.
Measurements:	nsaskyrad60sC1.b1: Sky Infra Red Temperature Minima(sky_ir_temp_min) Sky Infra Red Temperature Maxima(sky_ir_temp_max) Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std) Sky Infra-Red Temperature(sky_ir_temp)

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DQRID : D051202.1

Start Date	Start Time	End Date	End Time
11/04/2004	1900	09/09/2005	2142

Subject:	NSA/SKYRAD/C1 - Reprocess: Incorrect datalogger program affecting PIR1 and PIR2 downwelling longwave
DataStreams:	nsaskyrad20sC1.a0, nsaskyrad60sC1.b1
Description:	The excitation delays using in measuring the PIR1 case thermistor commonly named "Case1" and the PIR2 dome thermistor called "Dome2" were discovered to have been incorrectly set to 0 in the Skyrad datalogger program when the new CR23X based Skyrad loggers were installed. The result of no delay in these measurements results in an error in the measured resistance of the thermistors, Case1 and Dome2 and thus the calculated PIR1 and PIR2 irradiances. The errors are inversely proportial to temperature. Users can apply the temperature dependent irradiance corrections shown in the table below. Recall that the reported uncertainty of PIRs is typically +-.25% to +-.5% or 1 to 2 W/m2. The error corrections become the same order of magnitude or larger than the instrument uncertainties at or below 260K or 9F. Correction Table for Skyrad (TWP and NSA) DIR1 and DIR2 Irradiance DIR1 DIR1 DIR2 DIR2 T[F] Tcase[K] Correction[W/m2] Tdome[K] Correction[W/m2] 109.4 316.13 0.00 316.13 0.00 100.5 311.20 -0.15 311.20 0.12 93.2 307.14 -0.12 307.14 0.10 87.0 303.70 -0.10 303.70 0.08 81.6 300.70 -0.17 300.70 0.14 77.0 298.15 -0.22 298.15 0.18 59.4 288.35 -0.34 288.35 0.27 47.4 281.72 -0.23 281.72 0.18 38.5 276.74 -0.42 276.74 0.34 31.3 272.77 -0.48 272.77 0.38 25.4 269.48 -0.61 269.48 0.49 20.3 266.67 -0.67 266.67 0.54 16.0 264.25 -0.82 264.25 0.66 12.1 262.11 -0.98 262.11 0.79 8.7 260.19 -0.97 260.19 0.78 5.6 258.46 -1.07 258.46 0.86 2.7 256.89 -1.17 256.89 0.94 0.1 255.44 -1.33 255.44 1.07 -2.3 254.11 -1.41 254.11 1.13 -4.5 252.87 -1.43 252.87 1.15 -6.6 251.71 -1.52 251.71 1.22 -8.5 250.63 -1.63 250.63 1.31 -10.4 249.62 -1.73 249.62 1.39 -12.2 248.58 -1.79 248.58 1.44 -15.4 246.82 -1.93 246.82 1.55 -18.3 245.23 -2.05 245.23 1.65 -20.9 243.78 -2.22 243.78 1.78 -23.3 242.44 -2.36 242.44 1.89 -25.5 241.21 -2.58 241.21 2.07 -27.5 240.07 -2.65 240.07 2.13 -29.5 239.01 -2.75 239.01 2.21 -31.3 238.00 -3.02 238.00 2.42
Measurements:	nsaskyrad60sC1.b1: Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2, Maxima(down_long_hemisp_shaded2_max) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1, Minima(down_long_hemisp_shaded1_min) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2, Minima(down_long_hemisp_shaded2_min) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1(down_long_hemisp_shaded1) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2(down_long_hemisp_shaded2) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1, Standard Deviation(down_long_hemisp_shaded1_std) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1, Maxima(down_long_hemisp_shaded1_max) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2, Standard Deviation(down_long_hemisp_shaded2_std) nsaskyrad20sC1.a0: Instantaneous Downwelling Pyrgeometer Thermopile, Shaded Pyrgeometer2(inst_down_long_hemisp_shaded2_tp) Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded Pyrgeometer1(inst_down_long_shaded1_dome_resist) Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded Pyrgeometer2(inst_down_long_shaded2_dome_resist) Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded Pyrgeometer1(inst_down_long_shaded1_case_resist) Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded Pyrgeometer2(inst_down_long_shaded2_case_resist) Instantaneous Downwelling Pyrgeometer Thermopile, Shaded Pyrgeometer1(inst_down_long_hemisp_shaded1_tp)

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DQRID : D060630.37

Start Date	Start Time	End Date	End Time
11/04/2004	0300	12/21/2005	1853

Subject:	NSA/SKYRAD/C1 - Reprocess: Longwave Calibration error
DataStreams:	nsaskyrad60sC1.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:	nsaskyrad60sC1.b1: Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1(down_long_hemisp_shaded1) Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2(down_long_hemisp_shaded2)

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