NSA/GNDRAD/C1 - Noisy PIR Data

During the period referenced, the ground PIR was noisy in  
              comparison to the the sky PIR data.  (Note U021211.1 documents
              same problem for 9/1/98-2/28/99)

              The noise problem continued after the GNDRAD data logger was 
              replaced in late September. Particularly strong examples of the 
              noise can be seen in data from 11/10 - 11/19/99. The peak to 
              peak noise reaches 12 W/m2.

• pir1_mean
• pir1_max
• pir1_min
• pir1_sd

• pir1_max
• pir1_sd
• pir1_min
• pir1_mean

NSA/GNDRAD/C1 - IRT instrument maintenance

IRT offline while instrument cable was being rebuilt.  Data are bad.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

• irt1_max
• irt1_min
• irt1_sd
• irt1_mean

NSA/GNDRAD/C1 - IRT data noisy

After re-installation of the IRT on 12/10/99, the data are noisy. Source of the noise is 
believed to be the heater connected directly to the IRT.  Instrument was taken offline on 
12/30/1999 and shipped back to PNNL for repair/testing.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

• irt1_max
• irt1_min
• irt1_sd
• irt1_mean

NSA/GNDRAD/C1 - Instrument Maintenance

Tip tower was lowered for instrument maintenance.  Data taken 
              during this period are corrupt.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - Unreasonable PSP Data

During the darkness in the middle of this night, the PSP had a
              signal of 15 W/m2 over a three hour long period.  Cause unknown.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - PSP erroneously replaced by B&W

The PSP was erroneously replaced with a B&W on 6/13 and then 
              changed back to the PSP on 6/21. Data should still be good since
              appropriate calibration factors were applied.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - Instrument maintenance

The tip tower was lowered for instrument maintenance.  Data
              recorded are garbage.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - Bad calibrations applied

Bad data due to erroneous calibration constant in configuration 
              file

• pir1_mean
• psp1_sd
• pir1_sd
• psp1_min
• psp1_max
• psp1_mean
• pir1_max
• pir1_min

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max
• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/GNDRAD/C1 - Unexplained decrease in PSP and NET data values

100 W/m2 dip in the PSP data; NET data also affected. Possibly 
              due to operators working around the instruments.

• net
• net_min
• psp1_sd
• net_std
• net_mean
• net_sd
• psp1_min
• net_max
• psp1_max
• psp1_mean

• psp1_mean
• psp1_sd
• net_std
• net_max
• psp1_min
• psp1_max
• net_mean
• net_min
• net
• net_sd

NSA/GNDRAD/C1 - Data corrupted by brief spike

There is a unreasonable spike at this time. Simultaneous spikes on the NET, the PSP, and 
the PIR. Cause unknown, but most likely related to data logger.

• net
• psp1_sd
• net_std
• net_mean
• net_max
• psp1_mean
• pir1_max
• net_min
• pir1_mean
• pir1_sd
• net_sd
• psp1_min
• psp1_max
• pir1_min

• net_max
• psp1_min
• pir1_max
• net_mean
• net_min
• psp1_mean
• psp1_sd
• net_std
• psp1_max
• pir1_sd
• pir1_min
• pir1_mean
• net
• net_sd

NSA/GNDRAD/C1 - Rad instruments shaded by shelter

Each day around 02:00 - 03:30 GMT there is a unexpected decrease 
              for the PSP irradiance measurement due to a shading problem 
              associated with the swing set location relative to the instrument 
              shelter.  The GNDRAD NET and MFR instrument data also reflects 
              this problem.  Problem was resolved when the GNDRAD instruments 
              were moved to the 10 meter tip tower.

• net
• psp1_sd
• net_std
• net_mean
• net_max
• psp1_mean
• pir1_max
• net_min
• pir1_mean
• pir1_sd
• net_sd
• psp1_min
• psp1_max
• pir1_min

• net_max
• psp1_min
• pir1_max
• net_mean
• net_min
• psp1_mean
• psp1_sd
• net_std
• psp1_max
• pir1_sd
• pir1_min
• pir1_mean
• net
• net_sd

NSA/GNDRAD/C1 - PSP Data corrupted by brief spike

Large unreasonable narrow spike in PSP data; cause not known.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - No power to IRT

The data logger failed to supply power to the IRT.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• sfc_ir_temp_std
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)

NSA/GNDRAD/C1 - IRT cable failure

The IRT signal became very noisy and the problem was traced to the cable (after the 
instrument was returned to the vendor for diagnosis). The problem started occurring when ice 
surrounding the cable began to melt. The cable was repaired and the instrument reinstalled.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/GNDRAD/C1 - IRT returned to vendor

The IRT was returned to the vendor for diagnosis. It was found to be operating as expected 
and the signal noise problem was traced to the cable. The cable was repaired and the 
instrument reinstalled.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/GNDRAD/C2 - Upwelling PIR measurement - spikes in thermopile signal

ULH measurements have many spikes at this site.  On 2/03, the anomalous spikes become 
frequent and are very noticeable from 0027 - 0445 UTC.  Negative and positive spikes occur on 
seemingly random days until 5/27/2004.  Extensive troublshooting could not resolve 
problem, including a datalogger changout on 4/22.  Problem seems to have resolved itself with 
the last spikes occuring on 5/27/2004 approximately 1500GMT.  No problems with upwelling 
PIR noise are evident up until and after the conversion from Zeno to Campbell dataloggers 
on 11/22/2004.

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• pir1_sd
• pir1_mean
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• pir1_max
• up_long_hemisp_std
• pir1_min
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)

• Raw data stream - documentation not supported

• pir1_voltage
• inst_up_long_hemisp_tp

NSA/GNDRAD/C1 - IRT power failure

After performing corrective maintenance which involved turning off power to the GNDRAD 
instruments and data logger, power to the IRT was not restored. The problem was corrected by 
replacing the data logger.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/GNDRAD/C1 - Frosting/Condensation

The GNDRAD PIR and IRT comparison was showing the IRT 2-4 W/m^2 greater than the PIR.  
Suspected snow or frost on the instrument(s).  Corrective maintenance performed 10/15/04 at 
21:30 UT.  Optics of both instruments were cleaned.  Upwelling longwave measurement 
agreement restored (+/- 5 W/^2).

Although the relative performance (agreement) of the two instruments improved after 
corrective maintenance (+/- 2 W/m^2), no correction is suggested because the agreement remains 
with the estimated measurement uncertainty of +/- 4 W/m^2 (IRT) and +/-10 W/m^2 (Inverted 
PIR)

• Effective Surface (Skin) Temperature(sfc_ir_temp)
• net_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• up_long_hemisp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)

• Raw data stream - documentation not supported

• pir1_case_therm
• inst_up_long_hemisp_tp
• inst_up_long_case_resist
• pir1_dome_therm
• pir1_voltage
• inst_up_long_dome_resist

NSA/GNDRAD/C2 - Incorrect calibration coefficients applied to upwelling(Gndrad)PIR

An insitu test comparing the Gndrad PIR and the Gndrad IRT at the NSA was performed from 6 
Jan 2005 to 12 Jan 2005.  The radiometer mentor requested the Eppley single calibration 
coefficient for the PIR replace the 4 coefficients method developed by NREL.  The Grndrad 
PIR compared closer to the Gndrad IRT during this period. However, the radiometer mentor 
believes the 4 coefficient PIR irradiance measurements remains superior to the single 
coefficient Eppley PIR measurement method.  Further questions should be directed to the 
radiometer instrument mentor.

• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• pir1_sd
• pir1_mean
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• pir1_max
• up_long_hemisp_std
• pir1_min
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)

• Raw data stream - documentation not supported

NSA/GNDRAD/C1/C2 - Upwelling Shortwave data flagged bad are good.

The Upwelling Shortwave at both NSA facilites, C1 and C2, have been flagged red by the 
automatic tests because it is above empiical limits determined for a more southerly site 
(SGP) for this time of year. The data are good and should be flagged green. The test limits 
will be revised for NSA.

• 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)

NSA/GNDRAD/C1 - Power Disconnected Briefly

Power to the Tip tower and Groundrad was disconnected briefly while ground resistance 
measurements were made. 

The following comments are from Inst. Mentor Tom Stoffel: 

The longwave and shortwave irradiances from GNDRAD were not effected by the
temporary power disconnect.  Data are good.  This would have only stopped
the ventilators for a brief time and the data do not show any signs of poor
instrument responses.

The "sfc_ir_temp" data were, however, impacted during the brief (2
readings?) interval.

• Effective Surface (Skin) Temperature(sfc_ir_temp)
• external_voltage

NSA/GNDRAD/C1 - power outage affecting some GNDRAD sensors

During the power outage the upwelling global measurement from the PSP instrument shows a 
slight increase from -5 to +0 W/m2.  This is due to removal of thermal offsets induced by 
the AC heater during the power outage.  This heater is installed within the PSP 
ventilator - it is necessary for the NSA/C1 climate.
The upwelling longwave PIR instrument is unaffected due to case and dome temperature 
corrections.
The IRT is AC powered and was not operational during this time period.

• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Raw data stream - documentation not supported

• inst_sfc_ir_signal

NSA/GNDRAD/C1 - Reprocess: 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 are 
being reprocessing to remove the calibration bias.  Note, this also affected standard 
deviation, maximum and minimum data fields.

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

NSA/GNDRAD/C2 - Reprocess: 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 are 
being reprocessing to remove the calibration bias.  Note, this also affected standard 
deviation, maximum and minimum data fields.

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

NSA/GNDRAD/C1 - Incorrect calibration coefficients

BarrowC1, Gndrad. On Aug 11th the PSP-US was changed out and the Campbell program was 
changed to reflect this.  However, an old program that uses the 4 coefficient PIR cal factors 
was used. The PIR-UIR was not changed out, however, the logger program coeffs reverted 
back to the 4 Coeffcients.  The Eppley PIR-UIR coefficients for this S/N 30168F3 are :  
K0=0.0, K1(aka k)=.25253, K2= 1.0, K3=-4, Kr=0.0.

• net_min
• pir1_mean
• net_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• pir1_sd
• net_mean
• net_sd
• up_long_hemisp_std
• net_max
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• pir1_max
• pir1_min

• Raw data stream - documentation not supported

• pir1_case_therm
• inst_up_long_hemisp_tp
• inst_up_long_case_resist
• pir1_dome_therm
• pir1_voltage
• inst_up_long_dome_resist

• inst_up_long_dome_resist
• inst_up_long_hemisp_tp
• inst_up_long_case_resist

NSA/GNDRAD/C1 - Preventive maintenance

Preventive maintenance including ventilator repairs and instrument changeout during this 
time resulted in data that are not scientifically relevant.

• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• psp1_sd
• net_std
• net_mean
• net_max
• up_long_hemisp_std
• psp1_mean
• pir1_max
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• up_short_hemisp_std
• net_min
• pir1_mean
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• pir1_sd
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• net_sd
• psp1_min
• psp1_max
• 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)
• pir1_min

• inst_up_long_dome_resist
• inst_up_short_hemisp
• inst_up_long_hemisp_tp
• inst_up_long_case_resist

NSA/GNDRAD/C1 - Missing data

Data are missing and unrecoverable.

• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• inst_up_long_hemisp_tp
• alt
• lon
• inst_up_long_hemisp_case_temp
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• vBatt
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• inst_up_long_hemisp_dome_temp
• base_time
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• up_long_hemisp_std
• lat
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• logger_temp
• 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)
• time
• time_offset

NSA/GNDRAD/C1 - Reprocessed: Incorrect calibration coefficient

Installed Gndrad PSP (upwelling shortwave hemispheric irradiance) had calibration 
coefficient RS applied when it should have used Rsc.  ARM is using IR corrected coefficients 
Rsc@45 and CFc@45 for PSPs deployed at all facilities.  

PSP #32012F3 should use RSc@45=109.39 and not Rs@45=110.97.  

Reprocessed to correct upwelling shortwave hemispheric irradiance (US) by:
US(new) = (US(old) / 110.97 ) * 109.39

Reprocessing completed March 2008.

• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• inst_up_short_hemisp

NSA/GNDRAD/C1 - Upwelling PIR ventilator fan failure

The PIR exhibited a positive bias of approximately 6 W/m2 compared to the upwelling IRT 
due to ventilator fan failure.  Thus, the up_long_hemisp, data stream is high by about 6 
W/m2.    
   
Bias is not consistent and depends on atmospheric conditions. Either disregard the 
up_long_hemisp data or use the IRT for an estimate of the up_long_hemisp values during this time 
period.

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

• inst_up_long_hemisp_case_resist
• inst_up_long_hemisp_tp
• inst_up_long_hemisp_dome_resist

NSA/GNDRAD/C1 - Net radiometer removed

The net radiometer was removed from the NSA.C1 GNDRAD instrument suite on Feb 3, 2000.  
Net rad variables were filled with garbage data until Sept 23, 2000 and with missing values 
(-9999) until 20041103.  The net rad variables were removed from the netcdf files after 
20041103.

A reprocessing task (RID-526) has been submitted to the queue to address the need to add 
metadata to the NSA.C1 GNDRAD netcdf files documenting the missing data as well as to move 
toward a consistent datastream format throughout time.

• base_time

• net_mean
• net_std
• net_max
• net_min
• net
• net_sd

NSA/GNDRAD/C1 - Reprocess: IRT insufficiently heated

IRT had insufficient heating to maintain an internal reference temperature above 0 degrees 
C. Measurements of surface temperature were over-estimated when instrument was below 
freezing.

Data will be reprocessed, but users can correct data using the following correction 
factor:

If T_reference < -5?C, then

  IRT_corrected = (IRT_original - 32.993K)/0.87238

where T_reference can be estimated with the ambient temperature (e.g. 
inst_up_long_hemisp_dome_temp or inst_up_long_dome_temp)

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/GNDRAD/C2 - Reprocess: IRT insufficiently heated

IRT had insufficient heating to maintain an internal reference temperature above 0 degrees 
C. Measurements of surface temperature were over-estimated when instrument was below 
freezing.

Data will be reprocessed, but users can correct data using the following correction 
factor:

If T_reference < -5?C, then

  IRT_corrected = (IRT_original - 32.993K)/0.87238

where T_reference can be estimated with the ambient temperature (e.g. 
inst_up_long_hemisp_dome_temp or inst_up_long_dome_temp)

• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• sfc_ir_temp_std