SGP/SIRS/E10 - Noisy US(upwelling shortwave) data stream problem

Beginning 6/22, upwelling shortwave values frequently dropped well 
                below 0 W/m^2 (occasionally dropping below -50 W/m^2) during the
                nighttime hours.  Daytime values were excessively high and noisy.
                Instrument wiring was suspected and was corrected 07/02/2003.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Possible instrument drift

Downwelling shortwave values were too low, dropping below -10 W/m^2 
                 at night and reading 30-50 W/m^2 lower than DS calculated from 
                 direct and diffuse measurements during the day. This problem became 
                 more noticeable beginning on 10/14, when nighttime values began to 
                 drop below -10 W/m^2 consistently. The problem was corrected with 
                 the annual instrument changout on 10/23/03.  

                   Although the downwelling shortwave instrument (DS) appears to be the 
                 problem a more likely scenario is that the cable connections became 

                 thermopile.  The instrument changeout possibly reseated and corrected 
                 any poor connections.

• Raw data stream - documentation not supported

SGP/SIRS/E10 - Noisy UIR (upwelling longwave)data stream problem

Beginning 6/29, upwelling longwave (UIR) values frequently
                 exceeded quality control boundaries and appeared excessively 
                 noisy. Instrument wiring was suspected.  Data remained noisy 
                 until 08/06/2003 0500GMT when the UIR data returned to normal.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - PSP dome contamination

Measured values of diffuse shortwave downwelling radiation fluctuated below derived values 
of downwelling shortwave radiation by 50 W/m^2 during the afternoon hours under clear 
conditions. 

SMOS precipitation and wind speed data reveals rain and wind the night before on 02/20/03 
0100 GMT probably contaminated the PSP dome with dirt.

Precipitation of .25mm on 02/23/04 0300 seems to have effectively cleared the PSP dome 
since PSP data on 02/24/04 compares correctly to direct and diffuse components.

• Raw data stream - documentation not supported

SGP/SIRS/E10 - Reprocessing Notice (RID 290)

See below for details of reprocessing that was completed on 20150929.  Original 
DQR category: 4 (Red, Incorrect).

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During the pyrgeometer instrument (PIR) changeout a datalogger program was loaded with 
incorrect calibration coefficients for the shortwave instruments.  The affected measurements 
(instruments) were: downwelling diffuse (8-48), upwelling shortwave (PSP), direct normal 
(NIP) and downwelling shortwave (PSP)

Recalculate irradiances by determining original mV signal and reapplying the correct 
calibration coefficients.  For SGP/SIRS/E10 and each one minute irradiance value perform the 
following calculations by instrument:
DD(corrected) = (DD/107.24)*114.63
US(corrected) = (US/113.19)*117.46
NIP(corrected)= (NIP/120.17)*119.26
DS(corrected) = (DS/118.46)*122.78

• Raw data stream - documentation not supported

SGP/SIRS/E10 - tracker failure

During the night of 11/05-06 2004 the tracker failed at this location. During CM on 12/01, 
power cycling returned the tracker to service. However, tracker was not properly 
tracking in the AM. Tracker failed again sometime near 01/01/2005.  CM on reloaded the tracker 
program and realigned the tracker on 01/26/2005 1600GMT.  It has been working correctly 
since this time.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Unknown -failed PSP ventilator fan

Downwelling shortwave hemispheric (DSH) readings appear to have a slight to moderate 
negative offset from derived DSH values.  At night, this negative offset causes qc flags 
(since values are below the minimum threshold of -10 W/m^2).  Differences between derived and 
actual DSH values are sometimes on the order of 50 W/m^2 due to this offset. 
The offset was discovered to be due to a failed ventilator fan which is used to clear the 
dome of the PSP, the instrument which measures the DSH.  The ventilator likely seized or 
was intermittent and heated the PSP base giving an erroneous DSH reading.  Field techs 
replaced the fan on 01/25/2005 1745GMT.  The DSH has been reading normally since that time.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Downwelling Shortwave values low

Downwelling Shortwave Hemispheric (DSH) irradiance values from the pyranometer instrument 
were frequently below the MIN value of -10 W/m^2 at night.  DSH values also frequently 
disagreed with derived readings (at times well over 50 W/m^2 difference) during the 
daylight hours, especially in the morning. Field techs performed maintenance but could not find 
obvious instrument or connection problems.  

The low DSH values during nighttime were on the threshold of acceptable. Largest offsets 
acceptable with these pyranometers is typically -10 W/m2.  The large derived vs. actual 
DSH differences during the daylight hours are the subject of ongoing ARM investigation. No 
instrument problems could be identified.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Sensor cable failure

The short_direct_normal measurements from the normal incident pyrheliometer (NIP) 
instrument were missing beginning 6/13/2005 2115GMT.  On 6/20/2005 technicians found the NIP 
instrument cable broken, replaced it, and returned the instrument to service at 2200GMT.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Tracker Failure

On July 12th the SIRS tracker failed to wake up that morning.  On the 21st of July CM 
repaired the tracker.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Tracker failure

During this time range the solar tracker at E9 was not operating.  PM on 2/20 1800GMT 
power cycled the tracker and it resumed normal operation.

• Raw data stream - documentation not supported

SGP/SIRS/E9 - Downwelling SW cable problem

The down_short_diffuse_hemispheric data were erratic beginning 0109 GMT March 27 2007.  
Found rodents had chewed DD cable.  Repaired April 3rd 1625GMT.

Data are not recoverable. However, it can be reconstructed using the following shortwave 
instrument relationship on a minute by minute basis:

• Raw data stream - documentation not supported

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.

• Raw data stream - documentation not supported

• Raw data stream - documentation not supported