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)
• inst_up_long_case_temp
• Irradiance, shortwave, direct normal, pyrheliometer(short_direct_normal)
• 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, direct normal, pyrheliometer, maxima(short_direct_normal_max)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Irradiance, shortwave, downwelling, hemispheric, pyranometer, minima(down_short_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Maxima(down_short_hemisp_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• 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)
• Downwelling shortwave hemispheric irradiance, pyranometer(down_short_hemisp)
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer(down_long_hemisp_shaded)
• 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 -  Reprocessed and Corrected: Incorrect calibration coefficients

DATA REPROCESSED and CORRECTED: 

Incorrect calibration coefficients were used in the C1/SIRS data logger program. The 
PSP-US (upwelling shortwave global hemispheric), 30943F3 should be 126.93 instead Of 129.93 
[W/m2*mV]. The data were recalibrated to correct the error and reprocessed.

The data were archived in September 2016. Please retrieve the reprocessed data for use in 
your analysis.

You may find these data using the ARM Discovery tool at the following link:
http://www.archive.arm.gov/discovery/#v/results/s/finst::sirs/fsite::sgp/ffac::sgp.E1 


ORIGINAL DQR CATEGORY: Red( Incorrect)

REPROCESSED and CORRECTED DATA ARCHIVED:2016-09

REPROCESS IDENTIFICATION NUMBER: RID 386

---------------------------------------------------
--- ORIGINAL DQR DESCRIPTION ---
---------------------------------------------------


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)
• inst_up_long_dome_temp
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• 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)