SGP/SIRS/E24 - SIRS Signal Cable Damage at E24

Cattle from adjoining field had broken the electric fence wire around the equipment and
chewed radiometer cables in half adn damaged the shading arm(s) on the SciTec tracker.

The NIP and DD shortwave data collected during this time were recorded  by the
logger as 'over-range' or 'open-channel' (with corresponding data values stored as
'-99999') or a numeric value not representative of the real irradiance conditions
due to faulty connections.  Data for this period are to be considered MISSING.

• Raw data stream - documentation not supported

• Raw data stream - documentation not supported

SGP/SIRS/E24 - bad records in sneakernet data file

The sneakernet raw data file
  sgpsirsE24.01.20020203.052800.raw.200202031156.sneak.v0
has two corrupt data records.  If this file is used for a
future reprocessing effort, these two records should be 
discarded.  The remainder of the data from this file should
be carefully examined for additional abnormalities.

The two bad records are:
   25,2002,34,554,323.27, ...
and
   126,2002,34,605,321.73, ...

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Shadowband Misalignment/Tracker Failure

The solar tracker failed beginning around sunrise on 05/19/03 most likely during the 
previous nights reset. Failure time was approximate time of sunrise at 1000 on 05/19/03.  The 
tracker was power cycled and RTS at 1415 GMT on 05/28/03.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Shadowband Misalignment/Tracker Failure

Suntracker appears to have failed beginning on 6/3/03, most likely during previous night 
reset. Start time listed is approximate time of sunrise.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Shadowband Misalignment

Solar tracker stopped functioning on 7/17. Tracker power cycled on 
              07/24 and returned to normal tracking but failed again 7/25.  Power
              was cycled again 8/6 and tracker performance was sustained thereafter.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Bird Poop Contamination

Downwelling shortwave values were erratic during the day on 10/18 and in very poor 
agreement at times with downwelling shortwave values calculated from direct and diffuse 
measurements. Bi-weekly preventative maintenace records indicate bird poop was cleaned from the 
downwelling shortwave instrument on 10/29 at 16:30.  Review of maintenance records and 
instrument data indicate no bird contamination since 10/29.

Turkey vultures are the usual suspects in data quality problems at this facility. The 
RBD(rotating bird deterrent) had failed the week of 10/13 and is awaiting parts.  However, 
beginning in late October the birds had left the site.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - False signal

During clear-sky conditions, downwelling shortwave values spike downward approximately 50 
to 200 W/m^2 around 22:15 UTC for about 15 minutes. This problem occurs at about the same 
time for the same duration each day during the indicated period of the year.  This 
effect is due to a shadow from the Rotating Bird Deterrent (RBD) installed earlier in the year 
to prevent extensive bird droppings at the site.  The RBD is installed at such a 
location that it will partially shade the downwelling shortwave PSP from 19 October to 23 
February of the year.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Shadowband Misalignment

The NIP reported values close to zero and downwelling shortwave global and diffuse were 
equivalent due to tracker failure.  

Maintenance replaced tracker 2/27, but couldn't replace instruments until 03/02 2000 GMT 
due to bird poop contamination.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Instrument logger time problem, Unknown

Values of diffuse hemispheric shortwave radiation differ from derived values by at most 70 
Wm^(-2).  The incident appears to be isolated to 3/21, 3/22, and 3/23. An estimation of 
solar noon using downwelling shortwave hemispheric irradiance from the PSP shows solar 
noon to oocur at around 1845GMT on 3/21. Calculated solar noon occurs at E21 at 1831GMT for 
3/21/2004.  There appears to be a time discrepancy in the datalogger for these dates.  
04/01 is the next date with enough sun to determine solar noon and compare to calculated.  
The data from this date appears correct.  Ronald Reed [rreed@ops.sgp.arm.gov] reports 
the logger did not receive any reportable time updates during the late March time period.  
We don't know what happened during these three dates but from 3/24 on data looks acceptable.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Dirt on dome

Measured downwelling shortwave values differed from calculated 
              (direct + diffuse) by +/-100 W/m^2 in the afternoon.  Pattern of
              differences is indicative of a dirty downwelling shortwave dome.
              Maintenance on 6/9 cleaned water spots on the dome.  Other 
              downwelling instruments may have also been dirty during this 
              period.

• Raw data stream - documentation not supported

SGP/SIRS/E22 - Failed NIP sensor cable

The suntracker was driven past it optical limit switch and pulled the direct normal (NIP) 
instrument cable from its connector.

• Raw data stream - documentation not supported

SGP/SIRS/E24 - Erratic downwelling shortwave data

Downwelling shortwave hemispheric readings are occasionally erratic, jumping to very high 
or very low values for short periods of time. SGP PM techs reseated all Downwelling 
Shortwave PSP instrument connections on 3/17/2005 approx 1945GMT.  The problem did not reoccur 
after that time but the DS cable was replaced on 3/31/2005 approx 1815 GMT to ensure the 
problem did not reappear.

• Raw data stream - documentation not supported

SGP/SIRS/E24 - Dirt on dome

The Downwelling Shortwave Hemispheric (DSH) Irradiance data were erratic. The Pyranometer 
instrument dome at this site was likely dirty given the relatively large spread between 
the measured DSH and derived DSH readings during the middle part of the day (up to 50 
W/m^2). Rain on 04/06 most likely contributed to this problem.  Preventative maintenance on 
4/14 effectively cleaned the pyranometer dome.  Preventative maintenance reports indicate 
dry-water spots on dome when it was cleaned on 4/14.

• Raw data stream - documentation not supported

SGP/SIRS/E22 - Intermittent upwelling longwave data loss

Upwelling longwave hemispheric data drops out occasionally during the afternoon hours.  
Maintenance determined that the Upwelling LW Hemispheric irradiance instrument, the PIR, 
had a failed cable affecting only the thermopile measurement of this instrument.  Cable was 
replaced 7/20/05 2000GMT.

• Raw data stream - documentation not supported

SGP/SIRS/E24 - Reprocessing Notice (RID 216)

See below for details of reprocessing that was completed on 20160127.  Original 
DQR category: 4 (Red, Incorrect).

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

Calibration coefficient for the downwelling diffuse measurement (8-48 B&W Eppley 
instrument) was incorrect after the instrument replacement 8/18/2005.

Affected downwelling diffuse irradiance data can be corrected:
Irr(corr) = Irr(uncorr) / 122.85 * 112.85 (or a overall multiplier of .9186)

• Raw data stream - documentation not supported

SGP/SIRS/E24 - Reprocessing Notice (RID 257)

See below for details of reprocessing that was completed on 20160127.  Original 
DQR category: 4 (Red, Incorrect).

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

During the PIR coefficient change from 4/coeffs to 1/coeff, the downwelling diffuse 
hemispheric instrument (Eppley 8-48) coefficient was inadvertently changed to 122.85 and should 
have been 112.85 W/m2/mV. 

Perform the following calculation to correct the data, DD=downwelling diffuse instrument:  

  DD(new)[W/m2]=( DD(old)[W/m2]/122.85[W/m2\mV] )* 112.85[W/m2/mV]

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Roosting birds in field of view

The RBDD (Rotating Bird Deterrent Device) installed at E21 to prevent turkey vultures from 
roosting on the instrument boom failed resulting in noisy NIP (Short Direct Normal) and 
PSP (Short Global Hemispheric) data and a spike occurring around 2230 UTC everyday due to 
obstruction of the field of view.

Problem is intermittant due to moving birds.  Use data with discretion.  Follow ARM 
(DQMS3) flag recommendations for QC flags 02 or 03 found in section 5.1.4 of the SIRS handbook:
http://www.arm.gov/publications/tech_reports/handbooks/sirs_handbook.pdf

• Raw data stream - documentation not supported

SGP/SIRS/E22 - Reprocess: Incorrect calibration coefficients

NIP (short_direct_normal) 29541E6 had an incorrect calibration coefficient in the logger 
program. 128.97 should have been 126.67 [W/m2/mV].

• 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

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Ventilator Fan Failure

Start time is uncertain due to length of time this problem existed.  During the time frame 
specified the PSP (down_short_hemisp) and 8-48 (down_short_diffuse_hemisp) ventilator 
fans failed. PM replaced the fans 7/1/2008 1500. 
Ventilator failure does adversely affect thermopile radiometer measurements but the extent 
has not been quantified. The 8-48 is significantly less affected than the PSP. Mentor 
suggests using component sum method detailed in SIRS
instrument handbook where down_short_hemisp = down_short_diffuse +
short_direct_normal * cos (zenith angle) for each time record.

• Raw data stream - documentation not supported

SGP/SIRS/E21 - Reprocess: TimeCheck Error

The EF data system lost communication with the GPS likely starting on or around June 7th, 
the max time set For E21 was -5.04 sec. Since then, it has been increasing steadily:

Jun 8  Offset:    -267.449039
Jun 9  Offset:    -541.038624
Jun 10 Offset:    -814.469141
Jun 11 Offset:    -1076.862114
Jun 12 Offset:    -1350.330223
Jun 13 Offset:    -1623.639335
Jun 14 Offset:    -1897.047754
Jun 15 Offset:    -2170.552312
Jun 16 Offset:    -2422.130746
Jun 17 Offset:    -2684.607495
Jun 18 - Jun 22 (unknown)
Jun 23 Offset:    -4204.730579

If the E21 system clock drifts the E21 Datalogger clocks will be set to the same incorrect 
time. SIRS irradiance data will be correct but the corresponding time stamp cannot be 
accurately known or simply corrected for.

• Raw data stream - documentation not supported

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.

• Raw data stream - documentation not supported

• Raw data stream - documentation not supported