SGP/SIRS/C1 - Missing data due to Ice storm and clock problems

Data are missing due to power failures caused by an ice storm
and resulting system/instrument clock problems.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• up_short_hemisp_std
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• down_short_hemisp_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• East longitude(lon)
• inst_down_long_shaded_case_temp
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• base_time
• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• vBatt
• Altitude above mean sea level(alt)
• North latitude(lat)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std
• up_long_hemisp_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• inst_up_long_case_temp
• time_offset
• inst_down_long_shaded_dome_temp

SGP/SIRS/C1 - Discrepancy between measured and derived downwelling shortwave hemispheric

Measured values of downwelling hemispheric shortwave radiation were up to 40 W/m^2 higher 
than derived values during the afternoon hours.

Analysis reveals that this is likely an artifact of the cosine response of the particular 
installed PSP coupled with typical uncertainties of this set of installed radiometers.   
That is, this particular instrument cluster seems to be producing cumulative errors on 
the high side of accepted values.

The PSP contains the most uncertainty in measurement at this station. Users should use a 
derived value for the downwelling shortwave hemispheric irradiance (DS). Where DS = 
diffuse component + direct normal * cos(SZA) component described in the SIRS handbook Sec 7.2 
available at: http://www.arm.gov/publications/tech_reports/handbooks/sirs_handbook.pdf

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• down_short_hemisp_std
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1/E13 - Incorrect calibration coefficients

After the DIR changeout on 8/27, the DLH measurements at the central facility vary 
significantly between pyrgeometers by as much as 65 Wm^(-2).  It was discovered that the two 
downwelling pyrgeometers destined for C1 and E13 may have been swapped during installation.  
The instrument mentor is unsure of applied calibration coefficients during this DQR's 
time period.  Backing out new downwelling longwave irradiances would be difficult in this 
case. Fortunately, the problem period is less than a fortnight.

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• inst_down_long_shaded_case_temp
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• inst_down_long_shaded_dome_temp

SGP/SIRS/C1 - Reprocessed: UIR/DIR Incorrect calibration coefficients

The datalogger program at SIRS.C1 was automatically updated on 9/27/2004 1423GMT with an 
older program with incorrect UIR and DIR calibration coefficients.

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded_std
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• up_long_hemisp_std
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• inst_up_long_case_temp
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• inst_down_long_shaded_case_temp
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• inst_down_long_shaded_dome_temp

SGP/SIRS/C1 - Monthly Summary

dominant problem here is the daytime 3 component problem. Direct and Diffuse are
always too high and Global is too low. The problem occurs around the time that the
testing regime switches from twilight to daytime testing regimes or from daytime to
twilight. The flags occur in significant numbers on the 1st - 5th, 8th - 20th, 24th - 
28th,
30th, and 31st. The failures vary in magnitude and duration. The worst flags for a 
particular
day is typically high level yellow, with respect to this problem. Global goes below
daytime empirical limits on both the 5th and 6th for substantial periods of time. Diffuse
also goes below daytime empirical limits on the 6th in the evening. Upwelling Longwave is
below empirical limits on the 24th. This may not be a problem, as many sites exhibited
the same problem on the same night. Exceptionally cold temperatures may be the cause.
Direct also exceeds its daytime empirical limit on the 1st, 4th, 10th, 13th, 14th, and 
20th. This occurs
at the changeover from medium to high air mass and does not last for longer than 30 
minutes.

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)

SGP/SIRS/C1  - sun tracker power failure

C1 experienced a sun tracker power faulure.  The tracker was reset by onsite personnel 
shortly after the power failed.  Only shaded and direct instruments were affected - i.e. the 
downwelling diffuse measurement from the 8-48 B&W pyranometer and the direct normal 
measurement from the NIP pyrheliometer.  The downwelling longwave PIR data was unaffected by 
this event.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - Reprocessed: Longwave Calibration error

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 have been reprocessed to 
remove the calibration bias.  The reprocessed 60 second averaged data are based on 3 
instantaneous 20 second data records rather than on 60 1 second instantaneous data records. 
Still, these data are considered far superior to the originally processed data. The 
reprocessed data were archived in October 2006.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)

SGP/SIRS/C1 - Upwelling SW cable problem

Starting 11/13/2006, the C1 SIRS Upwelling Shortwave (up_short_hemisp) started to show 
large differences in comparison to co-located E13 SIRS and C1 IRT25m.  After much 
troubleshooting and gnashing of teeth it was discovered that rodents had chewed through the 
instrument cables at the bottom of the tilt tower. Cables were replaced 01/23/2007 1930GMT.

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)

SGP/SIRS/C1 - Reprocess: Incorrect calibration coefficients

Incorrection calibration coefficients were used in the C1/SIRS datalogger program. The 
PSP-US (upwelling shortwave global hemispheric), 30943F3 should be 126.93 not 129.93 
[W/m2/mV].

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)

SGP/SIRS/C1 - Upwelling LW cable problems

Troubleshooting of the upwelling shortwave instrument on Jan 3rd 2007 caused problems with 
the co-located upwelling longwave hemispheric irradiance Eppley PIR instrument (aka 
UIR).  Data dropouts persisted from this date to the final resolution of both shortwave and 
longwave instrument problems.  Rodents had chewed through the instrument cables.  The 
cables were replaced 01/23/2007 1930GMT.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• inst_up_long_case_temp
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• up_long_hemisp_std

SGP/SIRS/C1 - Sensor Cable Problem

Beginning October 3, 2007, the upwelling longwave irradiance (up_long_hemisp, aka "UIR") 
started to spike to unreasonable values positively offset from the co-located E13 by over 
100W/m2.  On January 17 2008 the UIR values become consistently bad due to bad UIR dome 
thermistor wiring.  Problem appears as a resistive offset in the dome thermistor but due 
to nature of failure (unknown cable problem) data correction would not yield any better 
data than the co-located E13 UIR instrument that is known to be operating correctly.  
Instrument cable replacement on 4/22 fixed the problem.

Thermopile data (netIR) from this instrument is good.  However, Incoming irradiance data 
is not correctable due to bad UIR dome thermistor wiring within the instrument cable.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• up_long_hemisp_std

SGP/SIRS/C1/E1/E10/E11/E12/E13/E15/E16/E18/E19/E2/E20/E21/E22/E24/E25/E27/E3/E4/E5/E6/E7/E8/E9 - Ice

Ice storms affected the SGP central and extended facilities starting Dec 10 0000GMT to 
mid/late December. Each facility was affected at various times and degrees dependant on 
elevation, latitude and whether power failed for short or extended periods of time.  By 
December 15th most ice had melted from the radiometers at all the faclities but power outages 
and tracker failures persisted at some stations.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• up_short_hemisp_std
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• down_short_hemisp_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• East longitude(lon)
• inst_down_long_shaded_case_temp
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• base_time
• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• vBatt
• Altitude above mean sea level(alt)
• North latitude(lat)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std
• up_long_hemisp_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• inst_up_long_case_temp
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• time_offset
• inst_down_long_shaded_dome_temp

SGP/SIRS/C1 - SW direct normal data drop out

NIP cable had failed during this time period.

Short_direct_normal data are not recoverable during this time period. However, it can be 
reconstructed using the following formula for each one minute data:
   short_direct_normal = (down_short_hemisp-down_short_diffuse_hemisp)/cos(zenith angle)

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - Reprocessed: Upwelling shortwave

The upwelling shortwave hemispheric data were bad 20090914-20091009 due to a broken 
instrument cable.  The cable was replaced on 10/09 at 1711 GMT but the leads were reversed. The 
leads were corrected 10/19 at 2001 GMT.

The data for 20090914-20091019 have been reprocessed. The bad data from 20090914-20091009 
were set to missing in the newly available reprocessed data set. The 20091009-20091019 
data were corrected by applying a (-1) multiplier.

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)

SGP/SIRS/C1 - Failed Upwelling SW cable

The upwelling shortwave hemispheric (up_short_hemisp) data were missing or incorrect due 
to a bad cable.  Cable was replaced on 6/30 and the problem was resolved.

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)

SGP/SIRS/C1 - NIP failure

The short_direct_normal (NIP instrument) cable failed during this time period.	Data are 
not recoverable.

Users can derive an estimate of direct normal values using the following formula:
short_direct_normal = (down_short_hemisp - down_short_diffuse_hemisp)/cos(zenith angle)

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - NIP Failure

The short_direct_normal (NIP instrument) cable failed (broken wire in NIP connector) 
during this time period. Data are not recoverable.


An estimate of direct normal values can be derived using the following formula:

short_direct_normal = (down_short_hemisp - down_short_diffuse_hemisp)/cos(zenith angle)

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - Reprocessing Notice (RID 734)

See below for details of reprocessing that was completed on 201410/24. Original DQR 
category: 4 (Red, Incorrect).

-----------------------------------------------------------

Calibration coefficient for downwelling longwave was incorrect for the specified period.

To correct the one minute data b1 datastream follow the procedure below:
1) Obtain the following variables from the 20s datastream for each one minute of the 
affected time range:
  inst_down_long_shaded_dome_resist (Rd)
  inst_down_long_shaded_case_resist (Rc)
  inst_down_long_hemisp_shaded_tp (tpDIR_mV)
                                         
2) using the 20s tp voltage in mV convert to uV.
  tpDIR[uV] = inst_down_long_hemisp_shaded_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=0.2762)
  WinDIR(W/m2)= [0.2762*tpDIR] + Sigma*Tc^4 -4*Sigma*(Td^4 - Tc^4)
  where, Sigma = 5.6704E-8 (Stefan-Boltzman Const)
                                      
5) Generate new 1 minute average from the 3 20-second measurements

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• inst_down_long_shaded_case_temp
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• inst_down_long_shaded_dome_temp

SGP/SIRS/C1 - Reprocessing Notice (RID 739)

See below for details of reprocessing that was completed on 20141024.  Original 
DQR category: 4 (Red, Incorrect).

-----------------------------------------------------------

The calibration coeff and serial number for the down_long_hemisp_shaded was incorrect 
during the period specified. 

Correct Instrument serial number = 30010F3 
                              K1 = 0.3125
Incorrect Instrument serial number = 30690F3 
                                K1 = 0.2762
 
Data will be reprocessed.

To correct the one minute data b1 datastream follow the procedure below:
1) Obtain the following variables from the 20s datastream for each one minute of the 
affected
time range:
  inst_down_long_shaded_dome_resist (Rd)
  inst_down_long_shaded_case_resist (Rc)
  inst_down_long_hemisp_shaded_tp (tpDIR_mV)
					 
2) using the 20s tp voltage in mV convert to uV.
  tpDIR[uV] = inst_down_long_hemisp_shaded_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=0.3125)
  WinDIR(W/m^2)= [0.3125*tpDIR] + Sigma*Tc^4 -4*Sigma*(Td^4 - Tc^4)
  where, 
        WinDIR = Corrected down_long_hemisp_shaded (W/m^2)
        Sigma =	5.6704E-8 (Stefan-Boltzman Constant)

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

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• inst_down_long_shaded_case_temp
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• inst_down_long_shaded_dome_temp

SGP/QCRAD/C1 - Reprocess: SW data require -1 multipler

Magnitude of data are correct, however, 2 wires were crossed producing negative values for 
SW Global Down, SW Global Up, SW Direct Normal, and SW Diffuse Down. Problem has been 
fixed at site.

Users of this data should multiply by -1 to get the correct values for SW Global Down, SW 
Global Up, SW Direct Normal, and SW Diffuse Down. Data will be reprocessed.

Documented in instrument DQR D000919.1.

• Best Estimate Global Downwelling Shortwave Hemispheric Irradiance(BestEstimate_down_short_hemisp)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)

SGP/QCRAD/C1 - Upwelling SW cable problem

Starting 11/13/2006, the C1 SIRS Upwelling Shortwave (up_short_hemisp) started to show 
large differences in comparison to co-located E13 SIRS and C1 IRT25m.  After much 
troubleshooting and gnashing of teeth it was discovered that rodents had chewed through the 
instrument cables at the bottom of the tilt tower. Cables were replaced 01/23/2007 1930GMT.

Documented in instrument DQR D061121.2

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)

SGP/QCRAD/C1 - Sensor cable problem

Beginning October 3, 2007, the upwelling longwave irradiance (up_long_hemisp, aka "UIR") 
started to spike to unreasonable values positively offset from the co-located E13 by over 
100W/m2.  On January 17 2008 the UIR values become consistently bad due to bad UIR dome 
thermistor wiring.  Problem appears as a resistive offset in the dome thermistor but due 
to nature of failure (unknown cable problem) data correction would not yield any better 
data than the co-located E13 UIR instrument that is known to be operating correctly. 
Instrument cable replacement on 4/22 fixed the problem.

Thermopile data (netIR) from this instrument is good.  However, incoming irradiance data 
is not correctable due to bad UIR dome thermistor wiring within the instrument cable. 

Documented in instrument DQR D071022.4.

• 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)

SGP/QCRAD/C1 - SW direct normal data drop out

NIP cable had failed during this time period.  Short_direct_normal data are not 
recoverable during this time period. However, it can be reconstructed using the following formula 
for each one minute data:
   short_direct_normal = (down_short_hemisp-down_short_diffuse_hemisp)/cos(zenith angle)

Documented in instrument DQR D090623.1

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)

SGP/QCRAD/C1 - Failed upwelling SW cable

The upwelling shortwave hemispheric (up_short_hemisp) data were missing or incorrect due 
to a bad cable.  Cable was replaced on 6/30 and the problem was resolved.

Documented in instrument DQR D100701.1

• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)

SGP/QCRAD/C1 - NIP failure

The short_direct_normal (NIP instrument) cable failed during this time period.	Data are 
not recoverable.

Users can derive an estimate of direct normal values using the following formula:
short_direct_normal = (down_short_hemisp - down_short_diffuse_hemisp)/cos(zenith angle)

Documented in instrument DQR D110628.2

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)

SGP/QCRAD/C1 - Case and dome temperatures not available

Longwave downwelling and upwelling case and dome temperatures are not available during 
this time period because they were not kept in the sirs.a1 files and sirs.b1 files are not 
available. This means that some longwave tests and corrections can't be applied.

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

SGP/SIRS/C1 - Missing NIP data

The short_direct_normal (direct beam, NIP instrument) values are missing during this time 
range due a broken signal wire. Problem was corrected on 2/6/2013

The short_direct_normal data are not recoverable. However, it can be derived using the 
following relationship and applied to the good one minute data from the global and diffuse 
instruments (the SIRS instrument handbook describes this in detail):
short_direct_normal(derived) = (down_short_hemisp - down_short_diffuse_hemisp)/cos(zenith 
angle)

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - NIP sensor failure

The short_direct_normal data are missing due to an instrument failure (NIP pyhrheliometer) 
likely due to a nearby lightning strike near the time of initial failure.

The short_direct_normal data are not recoverable during this time period.  However, direct 
normal data can be reconstructed from the down_short_diffuse_hemisp and 
down_short_hemisp using the following relationship for each data point:
short_direct_normal = (down_short_hemisp - down_short_diffuse_hemisp)/cos(zenith angle)

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - Solar tracker failure

Solar tracker was not operating correctly during the specified time periods. Data from the 
direct normal instrument (short_direct_normal), and diffuse shaded global instrument 
(down_short_diffuse) were adversely affected.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - Sensor alignment/level

During the time range specified the downwelling shortwave DS radiometer (down_short_hemisp 
measurement) was slightly out of level.  The affects on data quality are within the 
uncertainly of the instrument.  However, the derived DS value (component sum of direct and 
diffuse shortwave) should be used during this time period.  Any of the associated VAPs 
(QCRAD, Central Facility Best Estimate) use the component sum by default and will not be 
adversely affected.

• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• down_short_hemisp_std

SGP/SIRS/C1 - Instrument problem

The solar tracker was not functioning during the affected time ranges, resulting in 
incorrect data.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - Instrument

Short_direct_normal instrument not operating correctly during the affected time period.

• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)

SGP/SIRS/C1 - Solar tracker no functioning

The solar tracker was not functioning during the affected time range, resulting in 
incorrect data.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - Instrument

The solar tracker was not functioning during the affected time range, resulting in 
incorrect data.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP/SIRS/C1 - Instrument

Short_direct_normal and down_short_diffuse_hemispheric are incorrect during the affected 
time period

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std

SGP Site Power Outage Due to Winter Storm

On Saturday and Sunday, December 26 and 27th a powerful winter storm (Goliath) brought 
sleet and freezing rain to much of Oklahoma with wind gusts of 45 MPH at times. The result 
was very very slick roads and mass power outages.
 
The SGP central facility lost power at 8:55 PM CDT on Sunday, December 27th.  
The power was restored on 7:56 PM CDT on Wednesday, December 30th
 
Site Emergency procedures were activated and Technicians drained water out of instrument 
reservoirs and other measures as needed, early Monday morning.
 
On Wednesdays as roads and power started was restored to much of the areas east of I-35 , 
Site Technicians performed maintenance on several Extended Facilities.

During this period, data are potentially missing, incorrect, or suspect.  Carefully 
inspect the data before use.

• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• up_short_hemisp_std
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• down_short_hemisp_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• East longitude(lon)
• inst_down_long_shaded_case_temp
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• base_time
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• down_long_hemisp_shaded_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• vBatt
• Altitude above mean sea level(alt)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• North latitude(lat)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std
• up_long_hemisp_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• inst_up_long_case_temp
• time_offset
• inst_down_long_shaded_dome_temp

SGP/SIRS/C1 - Data System Upgrade: Data Missing

The site data system was upgraded.  Data were not collected during this period.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• qc_up_long_hemisp
• short_direct_normal_std
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• down_short_hemisp_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• qc_down_short_hemisp_min
• qc_short_direct_normal
• qc_down_short_diffuse_hemisp_max
• qc_down_short_hemisp
• qc_up_short_hemisp
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer, mifkba(down_long_hemisp_shaded_min)
• down_long_hemisp_shaded_std
• qc_up_short_hemisp_max
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• qc_up_short_hemisp_min
• North latitude(lat)
• qc_down_short_hemisp_max
• qc_down_short_diffuse_hemisp_min
• logger_temp
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• inst_down_long_shaded_dome_temp
• qc_up_long_hemisp_min
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• qc_down_short_diffuse_hemisp
• qc_time
• up_short_hemisp_std
• inst_up_long_dome_temp
• qc_short_direct_normal_min
• qc_down_long_hemisp_shaded_max
• qc_short_direct_normal_max
• qc_down_long_hemisp_shaded_min
• Upwelling Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• qc_up_long_hemisp_max
• East longitude(lon)
• inst_down_long_shaded_case_temp
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• base_time
• Irradiance, shortwave, upwelling, hemispheric, 10 meter(up_short_hemisp)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• vBatt
• time
• Altitude above mean sea level(alt)
• logger_volt
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• down_short_diffuse_hemisp_std
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• up_long_hemisp_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• qc_down_long_hemisp_shaded
• inst_up_long_case_temp
• time_offset

SGP/SIRS/C1 - PSP off-level

PSP was slightly off-level, but not enough to affect data quality. PSP level was adjusted 
02/23/16, 1917 GMT.

• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• down_short_hemisp_std

SGP/SIRS/C1 - Solar tracker not operating correctly

Solar tracker not operating correctly during affected time periods.

• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer, maxima(down_short_diffuse_hemisp_max)
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• short_direct_normal_std
• Irradiance, shortwave, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Irradiance, shortwave, downwelling, diffuse, hemispheric, pyranometer(down_short_diffuse_hemisp)
• down_short_diffuse_hemisp_std