TWP/QCRAD/C1 - LWdn ventilator failed

LWdn flux may be questionable during this time. Described in instrument DQR D080826.3:

During the time range specified the PIR2 output is questionable due to ventilator fan 
failure.
Although the PIR is temperature compensated, data review indicates that the PIR2 didn't
compare as well with PIR1. Typical differences during full sun are approximately 10 w/m2.
During this time period differences of 10-14 W/m2 were noted.

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

TWP/QCRAD/C1 - LWup and dn fluxes Tc/Td bad

Upwelling and downwelling longwave case and dome temperatures and fluxes appear to be 
incorrect during these times. No instrument DQRs exist for these time periods

• LWdnTc
• LWdnTd
• LWupTd
• LWupTc
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• LWdnTd
• LWdnTc
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• LWupTd
• LWupTc

• LWupTc
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• LWupTd
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• LWdnTd
• LWdnTc

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• LWupTc
• LWupTd
• LWdnTd
• LWdnTc
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

TWP/QCRAD/C1 - LWup connection bad

Data from the upwelling longwave radiometer are not valid for this period because of an 
incorrect connection to the data logger.

Described in instrument DQR D000711.68.

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

TWP/QCRAD/C1 - Spikes in temperature data

Beginning on 980212 (day #43) spikes began to occur in the surface temperature and water 
vapor pressure.  These spikes occur approximately once per hour (the spacing is very 
regular but occasionally an hour is skipped).  In the one-minute averaged data, the 
temperature spike lasts for only one minute and dips approximately 4-5 C below the actual 
temperature.  The one-minute standard deviation is more dramatic, rising from about 0.1 to about 
35.  The one minute temperature minimum is the most easily identifiable, each hour when 
the spike occurs, the minimum is -245.84.  The vapor pressure mean jumps from about 30 to 
over 50 and the standard deviation jumps from less than 1 to more than 200. This
problem was fixed by the RESET team on 980501.

Air temperature data is needed for tests on LW up and LW down pyrgeometer case and dome 
temperatures, and tests on the irradiances from upwelling LW/SW and downwelling LW.

Problem documented in instrument DQR D000718.11

• Temp_Air
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Temp_Air
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Temp_Air
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Temp_Air

TWP/QCRAD/C1 - Upwelling fluxes too low

The upwelling longwave and shortwave fluxes appear to be too low during these periods. It 
is possible that these are caused by inverting the radiometers but no instrument DQRs 
exist documenting the changes during these times.

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

TWP/QCRAD/C1 - Upwelling LW and SW radiometers inverted

The upwelling longwave and shortwave radiometers were inverted during this period for 
comparison with calibrated instruments.

Documented in instrument DQRs: D031215.2, D041106.2, D051123.2

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

TWP/QCRAD/C1 - Shortwave downwelling fluxes too low

Downwelling shortwave total, diffuse and direct normal flux values are low. Sometimes this 
also impacts the best estimate flux. The source of this problem is not clear. No 
instrument DQRs exist describing this problem.

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)

• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

TWP/QCRAD/C1 - Reprocess: Incorrect datalogger program affecting PIR1 and PIR2 downwelling 
longwave

Downwelling longwave calibration incorrect. Needs to be reprocessed. Described in 
instrument DQR D051202.5:

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 absolute value of 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. 

Irradiance Correction Table for Skyrad (TWP and NSA) DIR1 and DIR2 Irradiance

		DIR1	DIR1	DIR2	DIR2
	T[F]	Tc[K]   [W/m2]  Td[K]   [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

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

TWP/QCRAD/C1 - Reprocess: NIP calibration

Direct normal flux has incorrect calibration coefficient but can be fixed as described in 
instrument DQR D041106.1:

The tracker rotated and pulled the cable away from the NIP connector. In trying to 
discover
the problem with the NIP a new NIP was put in. When the problem turned out to be the 
cable,
the observers didn't put the former NIP back in. The NIP then in service was 31346E6
RS@45=8.1573 whereas the coefficients used were for the old NIP 299937E6 RS@45=7.8775

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

TWP/QCRAD/C1 - Upwelling flux incorrect

An incorrect datalogger configuration made upwelling fluxes incorrect during this time 
period. Described in instrument DQR D030317.3:

The configuration for the SMET was inadvertently loaded into the GNDRAD at Manus at 
03/03/2003 17:00 GMT. This error was found and corrected on 03/13/2003 at 21:30 GMT.  Because 
the wrong channels were addressed with incorrect sampling coefficients, it would be very 
difficult (and in some cases impossible) to reconstruct the data for this week and 3 day 
period.

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

TWP/QCRAD/C1 - Downwelling LW flux appears incorrect

Downwelling longwave fluxes values appear incorrect during this time. The cause for the 
strange values is not known. No instrument DQRs exist describing this problem.

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

TWP/QCRAD/C2 - MFRSR installation period

The MFRSR was being installed during this time, with many changes. All data should be used 
with caution during this time. 

Described in instrument DQR D020613.4.

• MFRSR_diffuse_hemisp_broadband
• MFRSR_hemisp_broadband
• MFRSR_flag
• MFRSR_direct_normal_broadband

• MFRSR_direct_normal_broadband
• MFRSR_diffuse_hemisp_broadband
• MFRSR_flag
• MFRSR_hemisp_broadband

• MFRSR_diffuse_hemisp_broadband
• MFRSR_flag
• MFRSR_hemisp_broadband
• MFRSR_direct_normal_broadband

• MFRSR_direct_normal_broadband
• MFRSR_hemisp_broadband
• MFRSR_flag
• MFRSR_diffuse_hemisp_broadband

TWP/QCRAD/C2 - Reprocess: Incorrect calibration coefficients

Incorrect calibration coefficients were used for downwelling shortwave and longwave 
irradiance. 

The following calculation method should be applied to correct the data, 

For the downwelling shortwave(PSPG) (DS)
Old Calibration coefficient [W/m2\mV] =119.68
New Calibration Coefficient [W/m2\mV] =125.94
DS(new_value)[W/m2]=( DS(old_value)[W/m2]/ 119.68 [W/m2\mV] )* 125.94 [W/m2/mV]

For the longwave irradiance (PIRG):

If the .a0 and .b1 data set available the following procedure should be applied for the 
downwelling LW
1) Obtain the following variables from the 20s datastream for each one minute of the 
affected time range:
  inst_down_long_hemisp1_dome_resist (Rd)
  inst_down_long_ hemisp1_case_resist (Rc)
  inst_down_long_ hemisp1_tp (tpDIR_mV)
					 
2) Using the 20s tp voltage in mV convert to uV.
  tpDIR[uV] = inst_down_long_hemisp1_tp [mV]*1000[uV/mV]

3) For each 20s data entry, convert Rd and Rc to temperature
  Td =1/ (a0 + (a1*LN (Rd*1000) + (a2*LN (Rd*1000)^3)))
  Tc = 1/ (a0 + (a1*LN (Rc*1000) + (a2*LN (Rc*1000)^3)))
  Where a0 = 0.0010295 
	a1 = 0.0002391
	a2 = 0.0000001568

4) Apply for each 20s data entry: (correct k1=0.2755)
  WinDIR(W/m^2)= [0.2755*tpDIR] + Sigma*Tc^4 -4*Sigma*(Td^4 - Tc^4)
  Where, 
	WinDIR = Corrected down_long_hemisp1 (W/m^2)
	Sigma = 5.6704E-8 (Stefan-Boltzman Constant)

				      
5) Generate new 1 minute average from the three 20-second measurements

For the longwave irradiance (PIRD):

If the .a0 and .b1 data set available the following procedure should be applied for the 
downwelling LW
1) Obtain the following variables from the 20s datastream for each one minute of the 
affected time range:
  inst_down_long_hemisp2_dome_resist (Rd)
  inst_down_long_ hemisp2_case_resist (Rc)
  inst_down_long_ hemisp2_tp (tpDIR_mV)
					 
2) Using the 20s tp voltage in mV convert to uV.
  tpDIR[uV] = inst_down_long_hemisp2_tp [mV]*1000[uV/mV]

3) For each 20s data entry, convert Rd and Rc to temperature
  Td =1/ (a0 + (a1*LN (Rd*1000) + (a2*LN (Rd*1000)^3)))
  Tc = 1/ (a0 + (a1*LN (Rc*1000) + (a2*LN (Rc*1000)^3)))
  Where a0 = 0.0010295 
	a1 = 0.0002391
	a2 = 0.0000001568

4) Apply for each 20s data entry: (correct k1=0.2786)
  WinDIR(W/m^2)= [0.2786*tpDIR] + Sigma*Tc^4 -4*Sigma*(Td^4 - Tc^4)
  Where, 
	WinDIR = Corrected down_long_hemisp2(W/m^2)
	Sigma = 5.6704E-8 (Stefan-Boltzman Constant)

				      
5) Generate new 1 minute average from the three 20-second measurements

This issue was also described in instrument DQR D031007.3.

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

TWP/QCRAD/C2 - Air temperature noisy or bad

Air temperature is bad or noisy during this time. 

Air temperature data is needed for tests on LW up and LW down pyrgeometer case and dome 
temperatures, and tests on the irradiances from upwelling LW/SW and downwelling LW.

There were no instrument DQRs on this problem at the time this report was submitted.

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• LWupTc
• LWupTd
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• LWdnTc
• LWdnTd
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Temp_Air

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• LWdnTd
• LWdnTc
• LWupTd
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• LWupTc
• Temp_Air
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• LWupTc
• LWupTd
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Temp_Air
• LWdnTd
• LWdnTc
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• LWdnTc
• LWdnTd
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Temp_Air
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• LWupTd
• LWupTc
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

TWP/QCRAD/C2 - Case and dome temperatures noisy or bad

Upwelling and downwelling longwave case and dome temperatures are noisy or bad during this 
time. Not all corrections and tests can be applied to LW fluxes as a result.

No instrument DQRs exist describing this problem.

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• LWupTc
• LWupTd
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• LWdnTc
• LWdnTd

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• LWdnTd
• LWdnTc
• LWupTd
• LWupTc

• LWupTc
• LWupTd
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• LWdnTd
• LWdnTc

• LWdnTc
• LWdnTd
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)
• LWupTd
• LWupTc

TWP/QCRAD/C2 - Downwelling LW too high

Downwelling longwave irradiance was too high compared to another instrument, possibly due 
to a bad connection. Problem described in instrument DQR D110317.3:

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

• Irradiance, longwave, downwelling, hemispheric(down_long_hemisp)

TWP/QCRAD/C2 - NIP cable bad

Shortwave direct normal irradiance data are missing or incorrect due to instrument cable 
failure. Described in instrument DQR D070206.1.

Note that fewer quality checks can be applied accurately to the BestEstimate data.

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

TWP/QCRAD/C2 - Direct normal reading too low

Direct normal irradiance data is bad. Described in instrument DQR D080313.2.

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

TWP/QCRAD/C2 - Tracker failure

Tracker appears to be out of alignment or inoperative during these times. The 
short_direct_normal (NIP) and down_short_diffuse_hemisp (8-48) data appear to be bad and not 
recoverable.

Several of these periods are documented in instrument DQRs:

D110831.1, D090328.1, D081222.3, D040107.1, D011207.1, D011019.8

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)

• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)

TWP/QCRAD/C2 - upwelling radiometers inverted

During calibration check periods the gndrad instruments are inverted
to compare with the skyrad pir and psp.

Most periods described in instrument DQRs: 

D990909.1, D030224.1, D031007.4, D040929.2, D050926.6

Last two periods identified manually from data.

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)