Data Quality Reports for Session: 103332 User: zhiansun Completed: 12/19/2006


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D051202.2NSA/SKYRAD/C2 - Reprocess: Incorrect datalogger program affecting PIR1 and PIR2
downwelling longwave
nsaskyrad20sC2.a0, nsaskyrad60sC2.b1
D060630.38NSA/SKYRAD/C2 - Reprocess: Longwave Calibration errornsaskyrad60sC2.b1
D060724.1NSA/SKYRAD/C2 - Summer solstice shading of radiometersnsaskyrad60sC2.b1


DQRID : D051202.2
Start DateStart TimeEnd DateEnd Time
11/16/2004000009/09/20052133
Subject:
NSA/SKYRAD/C2 - Reprocess: Incorrect datalogger program affecting PIR1 and PIR2 
downwelling longwave
DataStreams:nsaskyrad20sC2.a0, nsaskyrad60sC2.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 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:nsaskyrad60sC2.b1:
  • 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 Pyrgeometer1, Maxima(down_long_hemisp_shaded1_max)
  • Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1, Minima(down_long_hemisp_shaded1_min)
  • Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2, Maxima(down_long_hemisp_shaded2_max)
  • 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 Pyrgeometer2, Standard
    Deviation(down_long_hemisp_shaded2_std)

nsaskyrad20sC2.a0:
  • Instantaneous Downwelling Pyrgeometer Thermopile, Shaded Pyrgeometer1(inst_down_long_hemisp_shaded1_tp)
  • Instantaneous Downwelling Pyrgeometer Thermopile, Shaded Pyrgeometer2(inst_down_long_hemisp_shaded2_tp)
  • Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded
    Pyrgeometer2(inst_down_long_shaded2_case_resist)
  • Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded
    Pyrgeometer1(inst_down_long_shaded1_case_resist)
  • 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)


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DQRID : D060630.38
Start DateStart TimeEnd DateEnd Time
11/16/2004163012/21/20052244
Subject:
NSA/SKYRAD/C2 - Reprocess: Longwave Calibration error
DataStreams:nsaskyrad60sC2.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:nsaskyrad60sC2.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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DQRID : D060724.1
Start DateStart TimeEnd DateEnd Time
05/08/2000000008/05/20000000
05/08/2001000008/05/20010000
05/08/2002000008/05/20020000
05/08/2003000008/05/20030000
05/08/2004000008/05/20040000
05/08/2005000008/05/20050000
05/08/2006000008/05/20060000
Subject:
NSA/SKYRAD/C2 - Summer solstice shading of radiometers
DataStreams:nsaskyrad60sC2.b1
Description:
On and around the summer solstice, the NIP (Direct Normal shortwave measurement) and PSP 
(global hemispheic shortwave measurement) radiometers are shaded by other instruments or 
support structures. Shading azimuths have been determined for this site.  The radiometer 
mentor suggests not using the data from the NIP and PSP radiometers when the sun is within 
the following azimuth bounds (typically from May 8th to August 5th of each year):
Instr   Obstruction   AzStart   AzEnd
NIP     rad table     356       17
PSP     mfrsr         341       353

Note: There are a number of objects near the NW,N and NE horizon that may affect sunrise 
data near the summer soltice.
Measurements:nsaskyrad60sC2.b1:
  • PSP1 unshaded standard deviation(psp1_sd)
  • Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
  • Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Minima(down_short_hemisp_min)
  • PSP shaded standard deviation(psps_sd)
  • PSP shaded mean(psps_mean)
  • NIP maximum(nip_max)
  • NIP mean(nip_mean)
  • Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer(down_short_hemisp)
  • Shortwave Direct Normal Irradiance, Pyrheliometer, Standard Deviation(short_direct_normal_std)
  • PSP1 unshaded maximum(psp1_max)
  • Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
  • Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Standard
    Deviation(down_short_hemisp_std)
  • NIP minimum(nip_min)
  • NIP standard deviation(nip_sd)
  • PSP1 unshaded minimum(psp1_min)
  • PSP shaded minimum(psps_min)
  • PSP1 unshaded mean(psp1_mean)
  • Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Maxima(down_short_hemisp_max)
  • Shortwave Direct Normal Irradiance, Pyrheliometer(short_direct_normal)
  • PSP shaded maximum(psps_max)


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