NSA/SKYRAD/C1 - Reprocess: PIR identified as unshaded is really shaded

On 5/15/02 the Global PIR was moved from the unshaded position on the Skyrad stand to a 
shaded spot on the tracker.  It is still using the same Logger channel as it did as an 
unshaded PIR even though it is now shaded.

• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2(down_long_hemisp2)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer2(inst_down_long_hemisp2_tp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_case_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Minima(down_long_hemisp2_min)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_dome_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Standard Deviation(down_long_hemisp2_std)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Maxima(down_long_hemisp2_max)

NSA/SKYRAD/C1 - Unshaded PIR data unreasonable

Periods of very large negative values. 
Negative readings of thermistors caused concurrent calculation 
in logger of temperature to fail.

• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - PIR data suspect

PIR shaded and PIR unshaded show unusual differences during this time period, frosting or 
icing is the most probable explanation but we don't know for sure.

• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - Shaded PIR data unreasonable

Periods of very large negative values. 
Negative readings of thermistors causes concurrent calculation 
in logger of temperature to fail.

• PIR shaded minimum(pirs_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)

NSA/SKYRAD/C1 - Corrupted Shaded PIR data

Erroneous data due to file truncation problem during logger download and corresponding 
ingest problems when the truncated lines were read. Problem was identified in a PIF 
submitted by Rune Storvold

• PIR shaded minimum(pirs_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)

NSA/SKYRAD/C1 - Shaded PIR data unreasonable

There was  a 10-25 W/m2 spike in data probably due to operator working around instrument 
or cleaning it.

• PIR shaded minimum(pirs_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)

NSA/SKYRAD/C1 - Unshaded and Shaded PIR data bad

Large unreasonable spikes and some missing data points. Cause of problem unknown.

• PIR shaded minimum(pirs_min)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - PIR data suspect

PIR shaded and PIR unshaded show unusual differences during this time period, frosting or 
icing is one possible explanation but we don't know.

• PIR shaded minimum(pirs_min)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - Corrupted Unshaded PIR data

Erroneous data due to file truncation problem during logger download and corresponding 
ingest problems when the truncated lines were read. Problem was identified in a PIF 
submitted by Rune Storvold

• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - Shaded PIR data suspect

The instrument had incorrect calibration settings on two accounts: 1. From 12/09 to 12/12, 
the calibration was set incorrectly. 2. The dome correction coefficients were not 
properly set until the early morning of 12/14. The erroneous settings caused an error probably 
less than 4%.

• PIR shaded minimum(pirs_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)

NSA/SKYRAD/C1 - PIR data suspect

The PIR unshaded and the PIR shaded have a persistent offset between them, ranging from 0 
to 10 W/m2. It is particularly apparent during clear sky. The line of sight of the PIRd 
is obstructed making it difficult to assess the problem. The instrument was moved to its 
proper location in early February. The problem seems to have resolved itself with the move.

• PIR shaded minimum(pirs_min)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - Shaded PIR data incorrect

There were two sudden increases (about 50-100 W/m2) at 23:00 and 24:00.

• PIR shaded minimum(pirs_min)
• PIR shaded mean(pirs_mean)
• PIR shaded maximum(pirs_max)
• PIR shaded standard deviation(pirs_sd)

NSA/SKYRAD/C1 - Spikes in Unshaded PIR data

There was  a 10-25 W/m2 spike in data probably due to operator working around instrument 
or cleaning it.

• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - Discontinuity in Unshaded PIR data

There was a sudden increase in irradiance (from 140 to 190 W/m2) at 02/03/99 23:00.

• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/SKYRAD/C1 - Unshaded PIR data incorrect

Data from this time period is incorrect because instrument was swapped out for 
calibration and correct calibrations were not entered for replacement.  Some 
missing data during this time interval as well

• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/GNDRAD/C1 - Unreasonable/missing PIR data due to maintenance

During this period, there are data gaps and the data that were
collected are unreasonable.  Instrument maintenance was being
performed

• PSP1 unshaded mean(psp1_mean)
• PSP1 unshaded standard deviation(psp1_sd)
• Net Radiation, Standard Deviation(net_std)
• Net Radiation, Maxima(net_max)
• PSP1 unshaded minimum(psp1_min)
• PSP1 unshaded maximum(psp1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• NET mean(net_mean)
• PIR1 unshaded mean(pir1_mean)
• Net Radiation, Minima(net_min)
• Net Radiation(net)
• NET standard deviation(net_sd)

NSA/GNDRAD/C1 - Noisy PIR Data

During the period referenced, the ground PIR was noisy in comparison to the sky PIR data.  
At the end of November, the noise increased to roughly 10 W/m2 from peak to peak.  After 
12/23/98, the noise decreased in amplitude but still had noisy patterns.  

On 01/17-18/99, there was an increase again in the noise level (4 GMT 01/17 - 5 GMT 
01/18). During this period the gndrad IRT data also exhibited noise patterns (the IRT was not 
operational).

In February, the instrument exhibited large noise variations again.  On 02/16, a wiring 
problem was corrected and the noise dropped back to 1-5 W/m2.  However, the noise levels 
began to increase again.

• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/GNDRAD/C1 - PIR1 Calibration problems resulted in small error

The dome correction coefficients were not properly reset in calibration file until the 
early morning of 12/15. These errors probably account for less than 4% in error.

• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/GNDRAD/C1 - PIR offline

The PIR was taken off line during this period; data recorded 
              during this period are garbage.

• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/GNDRAD/C1 - Instrument maintenance

Instrument replaced. Data affected by the work done during this time.

• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded minimum(pir1_min)
• PIR1 unshaded mean(pir1_mean)

NSA/GNDRAD/C1 - Bad PSP calibrations applied

The ground radiation data are bad during this period due to 
              erroneous calibration factors in the logger configuration file.

• PSP1 unshaded mean(psp1_mean)
• PSP1 unshaded standard deviation(psp1_sd)
• Net Radiation, Standard Deviation(net_std)
• Net Radiation, Maxima(net_max)
• PSP1 unshaded minimum(psp1_min)
• PSP1 unshaded maximum(psp1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• NET mean(net_mean)
• PIR1 unshaded mean(pir1_mean)
• Net Radiation, Minima(net_min)
• Net Radiation(net)
• NET standard deviation(net_sd)

NSA/SKYRAD/C1 - NIP shaded by skyrad stand around local midnight

Around local midnight 9:30-10:30 GMT during summer clear sky the normal incidence 
pyranometer is shaded by the instrument stand.This causes the reading to be 0 W/m2. If cosine 
correction is applied for irradiance calulations this effect is negligible due to the low 
solar angle.

• NIP maximum(nip_max)
• NIP standard deviation(nip_sd)
• NIP minimum(nip_min)
• NIP mean(nip_mean)

NSA/SKYRAD/C1 - PSP shaded by MFRSR after local midnight

Just past local midnight (11:00-11:40 GMT during summer clear sky) the global 
hemispherical pyranometer is shaded by the MFRSR instrument for about 40 minutes. This causes the 
reading to be 0 W/m2. This effect would be negligible in a daily average due to the low 
solar angle.

• PSP1 unshaded standard deviation(psp1_sd)
• PSP1 unshaded mean(psp1_mean)
• PSP1 unshaded minimum(psp1_min)
• PSP1 unshaded maximum(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)
• Surface Infra-Red Temperature, Standard Deviation(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)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)

NSA/SKYRAD/C1 - IRT measurements during precipitation events

The IRT measurement of sky/cloud temperature was in question during precipitation events 
because rain or snow could accumulate in the upward-pointed lens barrel. This was 
corrected by reorienting the IRT to measure the sky temperature as reflected by a gold mirror.

• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT failed

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT incorrectly configured

The IRT was removed for repair and replaced with a
spare that was not configured properly.  Data are incorrect.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT incorrect min/max value

The values of valid_min and valid_max for field sky_ir_temp were incorrectly assigned to 
-49.7 and +50.0 C, respectively. The actual values should be -60 and +40 C.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT measurements during precipitation events

The IRT measurement of sky/cloud temperature was in question during
precipitation events because rain or snow could accumulate in the
upward-pointed lens barrel. This was corrected by reorienting the
IRT to measure the sky temperature as reflected by a gold mirror.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

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)
• Surface Infra-Red Temperature, Standard Deviation(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)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/SKYRAD/C1 - Downwelling IRT bias

The downwelling IRT was measuring higher sky/cloud temperatures than the AERI. The problem 
was corrected when the mirror was replaced.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - Tracker Inoperative

A blown fuse resulted in the tracker not shading the PIR and B&W
and the NIP not following the sun.

• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)

NSA/SKYRAD/C1 - itermittant IRT bias

A problem with the SKYRAD IRT that itermittantly produced a gradual increase in the sky 
temperature measurement then a sudden correction, as compared to AERI, appears to have been 
caused by a combination of a failing IR detector, a poor signal cable, a contaminated 
(with condensation or frost) mirror or lens, and low ambient temperatures. The positive 
bias was apparently not consistant in either frequency or duration but on days when the 
unusual behavior is observed, it usually occurred from about 00:00 to 06:00 local time. 

The instrument was repaired and recalibrated and the signal cable replaced.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

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)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/SKYRAD/C1 - IRT failure

The IRT failed and was replaced with a spare.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

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 (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)

• null(Raw data stream - documentation not supported)

• Instantaneous Surface Infra-Red Signal(inst_sfc_ir_signal)

NSA/SKYRAD/C1 - Power outage affecting some SKYRAD instruments

During the power outage the downwelling global measurement from the PSP instrument and 
downwelling diffuse 8-48 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 downwelling 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.

• null(Raw data stream - documentation not supported)

• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Sky Infra-Red Temperature(sky_ir_temp)

• Instantaneous Downwelling Hemispheric Shortwave, Unshaded Pyranometer Thermopile
  Voltage(inst_global)
• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Sky/Cloud Infrared(inst_sky_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.

• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)

NSA/SKYRAD/C1 - Missing data

Data are missing and unrecoverable.

• Battery Voltage(vBatt)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer2(inst_down_long_hemisp2_tp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• lat(lat)
• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1(down_long_hemisp1)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Dummy altitude for Zeb(alt)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Logger panel temperature(logger_temp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1, Minima(down_long_hemisp1_min)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer1(inst_down_long_hemisp1_tp)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_dome_temp)
• Time offset of tweaks from base_time(time_offset)
• Sky Infra-Red Temperature(sky_ir_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1, Maxima(down_long_hemisp1_max)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_case_temp)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer1(inst_down_long_hemisp1_dome_temp)
• time(time)
• lon(lon)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Minima(down_long_hemisp2_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Maxima(down_long_hemisp2_max)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Standard Deviation(down_long_hemisp2_std)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer1(inst_down_long_hemisp1_case_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2(down_long_hemisp2)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• base time(base_time)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1, Standard Deviation(down_long_hemisp1_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)

NSA/GNDRAD/C1 - Missing data

Data are missing and unrecoverable.

• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Instantaneous Upwelling Pyrgeometer Thermopile(inst_up_long_hemisp_tp)
• Dummy altitude for Zeb(alt)
• lon(lon)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Temperature(inst_up_long_hemisp_case_temp)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Battery Voltage(vBatt)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Temperature(inst_up_long_hemisp_dome_temp)
• base time(base_time)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• lat(lat)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Logger panel temperature(logger_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• time(time)
• Time offset of tweaks from base_time(time_offset)

NSA/SKYRAD/C1 - Reprocessed: Incorrect calibration coefficient

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

PSP #32026 should use RSc@45=8.7578 ?V/W/m? and not Rs@45=8.6335.

Reprocessed to correct downwelling shortwave hemispheric irradiance (DS) by:
DS(new) = (DS(old) / 115.83 ) * 114.18

Reprocessing completed March 2008.

• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)

• Instantaneous Downwelling Hemispheric Shortwave, Unshaded Pyranometer Thermopile
  Voltage(inst_global)

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 (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)

• Instantaneous Upwelling Shortwave Hemispheric Irradiance, Pyranometer(inst_up_short_hemisp)

NSA/SKYRAD/C1 - Instrument cleaning effects

Starting Dec 16th the Skyrad PIR1 and PIR2 (down_long_hemispheric)started differing by 
greater than 30W/m2 at times.  This is much greater than expected  for these instruments 
(typical is <10-15 W/m2).  NSA OMIS reports and observer comments reveal that PM 
periodically clean the snow from the IRT and ventilator fans on Skyrad and Gndrad.  In the case of 
the Skyrad PIRs, one lies in the wind shadow of the other and builds up more snow which is 
periodically cleaned out and then builds up again causing the PIR1 PIR2 discrepancies.

Disregard down_long_hemispheric during this time period. However, data suggests PIR2 is 
most likely at fault - potentially use PIR1 data during this time period.

• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer2(inst_down_long_hemisp2_tp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_case_temp)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer1(inst_down_long_hemisp1_dome_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Minima(down_long_hemisp2_min)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1(down_long_hemisp1)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Maxima(down_long_hemisp2_max)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2, Standard Deviation(down_long_hemisp2_std)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer2(down_long_hemisp2)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Pyrgeometer1(inst_down_long_hemisp1_case_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1, Minima(down_long_hemisp1_min)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer1(inst_down_long_hemisp1_tp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1, Standard Deviation(down_long_hemisp1_std)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Pyrgeometer2(inst_down_long_hemisp2_dome_temp)
• Downwelling Longwave Hemispheric Irradiance, Pyrgeometer1, Maxima(down_long_hemisp1_max)

• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer1(inst_down_long_hemisp1_dome_resist)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer2(inst_down_long_hemisp2_tp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer2(inst_down_long_hemisp2_case_resist)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer2(inst_down_long_hemisp2_dome_resist)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer1(inst_down_long_hemisp1_tp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer1(inst_down_long_hemisp1_case_resist)

NSA/SKYRAD/C1 - IRT mirror heater failure

The heater of the IRT gold mirror failed due to a broken wire (that probably occurred on 
12/13 during maintenance of the solar tracker) allowing snow and frost to accumulate on 
the mirror until it was cleared during daily preventative maintenance. The problem was 
corrected when the heater wires were replaced.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

• Instantaneous Sky/Cloud Infrared(inst_sky_ir_signal)

NSA/SKYRAD/C1 - Direct and Diffuse incorrect

The short_direct_normal (NIP) instrument and cable were damaged by tracker rewind 
malfunction. Tracker and NIP replaced on 4/22 2200GMT but tracker not operational until 4/23 
1815GMT.  Thus, down_short_diffuse_hemisp (8-48) was not shaded 4/22 to 4/23.

Do not use 8-48 data from 4/22 to 4/23. NIP data is not recoverable during entire time but 
can be estimated using component sum for each 1 minute data: Direct = (global - 
diffuse)/cos(zenith angle)

• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)

• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)

NSA/SKYRAD/C1 - Tracker inoperative

Tracker stopped working at this site during the time range specified. Reason for failure 
is unknown.  Tracker power cycled and restarted by maintenance 06/30 2008 1740 GMT.

The short_direct_normal (NIP) and down_short_diffuse_hemisp (8-48) data are bad during 
this time.  Data are not recoverable.

• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)

• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)

NSA/GNDRAD/C1 - IRT not connected

The IRT was unplugged from the Zeno data logger on 12/10/1998 for a interference test and 
when it was plugged back in on 12/22, the connector at the data logger was damaged. The 
data logger and connecter were replaced on 1/20/1999.

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

NSA/GNDRAD/C1 - Reprocess: IRT scale factor

The IRT scale factors in the data logger were incorrectly set to m = 100 degC/V, b = -60 
degC. They were corrected to 25 degC/V and -50 degC.

Correct with: IRT(C) = (IRT_bad+60C)*(25/100) - 50C

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

NSA/GNDRAD/C1 - IRT failed

The IRT failed and was replaced with one installed inside an insulated enclosure.

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

NSA/GNDRAD/C1 - IRT incorrect

The IRT data were very noisy and unrepresentative.

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

NSA/GNDRAD/C1 - IRT scale factor

The IRT scale factors in the data logger were incorrectly set to m = 100 degC/V, b = -60 
degC. They were corrected to 25 degC/V and -50 degC.

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

NSA/SKYRAD/C1 - IRT signal bias

Additional heat tape that was installed around the IRT appears to have produced a negative 
bias of about 10 deg (at a sky temperature of -30C). This was corrected when the heat 
tape was replaced with thermostatically-controlled 75W heaters (that were still 
insufficient in maintaining the IRT above freezing - D990924.2).

• IRT1 mean(irt1_mean)
• IRT1 minimum(irt1_min)
• IRT1 maximum(irt1_max)

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.

• Instantaneous Upwelling Pyrgeometer Dome Thermistor Temperature(inst_up_long_hemisp_dome_temp)
• Instantaneous Upwelling Pyrgeometer Thermopile(inst_up_long_hemisp_tp)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Temperature(inst_up_long_hemisp_case_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)

• Instantaneous Upwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer(inst_up_long_hemisp_case_resist)
• Instantaneous Upwelling Pyrgeometer Thermopile(inst_up_long_hemisp_tp)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer(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(base_time)

• NET mean(net_mean)
• Net Radiation, Standard Deviation(net_std)
• Net Radiation, Maxima(net_max)
• Net Radiation, Minima(net_min)
• Net Radiation(net)
• NET standard deviation(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)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

NSA/SKYRAD/C1 - Reprocess: IRT insufficiently heated

IRT had insufficient heating to maintain an internal reference temperature above 0 degrees 
C. Measurements of sky 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_down_long_hemisp_dome_temp or inst_down_long_dome_temp)

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD/C1 - IRT covered with snow

The IRT mirror was buried with snow by the dew-line snow-blower.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)

NSA/SKYRAD - Barrow SKYRAD PIRD Misconfiguration 12/9 - 12/12/98

The PIRD was incorrectly set from 12/9/98 to 12/12/98 that resulted in an 
error of approximately 3.7% (was set to 243902 instead of 235294).

• Dummy altitude for Zeb(alt)
• IRT1 standard deviation(irt1_sd)
• NIP mean(nip_mean)
• Time offset of tweaks from base_time(time_offset)
• PIR shaded minimum(pirs_min)
• IRT1 mean(irt1_mean)
• PIR shaded maximum(pirs_max)
• PSP1 unshaded mean(psp1_mean)
• UVB minimum(uvb_min)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded minimum(pir1_min)
• IRT1 minimum(irt1_min)
• base time(base_time)
• NIP minimum(nip_min)
• lat(lat)
• PSP1 unshaded minimum(psp1_min)
• PSP1 unshaded maximum(psp1_max)
• IRT1 maximum(irt1_max)
• PIR shaded mean(pirs_mean)
• External voltage(external_voltage)
• PSP shaded standard deviation(psps_sd)
• NIP maximum(nip_max)
• UVB mean(uvb_mean)
• NIP standard deviation(nip_sd)
• PSP1 unshaded standard deviation(psp1_sd)
• GPS raw data filename(filename)
• UVB maximum(uvb_max)
• Bit data. See details.(bit_data)
• PSP shaded maximum(psps_max)
• lon(lon)
• UVB standard deviation(uvb_sd)
• PIR1 unshaded standard deviation(pir1_sd)
• PIR shaded standard deviation(pirs_sd)
• Battery Voltage(internal_voltage)
• PIR1 unshaded mean(pir1_mean)
• Logger panel temperature(logger_temp)
• PSP shaded mean(psps_mean)
• PSP shaded minimum(psps_min)

• Instantaneous PIR2 dome thermistor(pir2_dome_therm)
• Time offset of tweaks from base_time(time_offset)
• Instantaneous PIR2 uncorrected irradiance(pir2_uncorr_irradiance)
• base time(base_time)
• Instantaneous UVB temperature(uvb_temp)
• Instantaneous UVB uncorrected irradiance(uvb_uncorr_irradiance)
• lat(lat)
• Instantaneous PIR2 case thermistor(pir2_case_therm)
• Instantaneous PIR1 uncorrected irradiance(pir1_uncorr_irradiance)
• Instantaneous PIR1 case thermistor(pir1_case_therm)
• Dummy altitude for Zeb(alt)
• Instantaneous PIR1 dome thermistor(pir1_dome_therm)
• lon(lon)
• GPS raw data filename(filename)

NSA/SKYRAD/C1 - IRT removed for repair

The instrument was damaged by internal water condensation caused by the 
exterior foam insulation used to keep the IRT above freezing. It was returned 
in July 1998 to the manufacturer for repair.

• null(Raw data stream - documentation not supported)

• IRT1 mean(irt1_mean)
• IRT1 minimum(irt1_min)
• IRT1 standard deviation(irt1_sd)
• IRT1 maximum(irt1_max)

NSA/SKYRAD/C1 - IRT removed from service

Instrument was removed to check performance.

• null(Raw data stream - documentation not supported)

• IRT1 mean(irt1_mean)
• IRT1 minimum(irt1_min)
• IRT1 standard deviation(irt1_sd)
• IRT1 maximum(irt1_max)

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)

• IRT1 maximum(irt1_max)
• IRT1 minimum(irt1_min)
• IRT1 standard deviation(irt1_sd)
• IRT1 mean(irt1_mean)

NSA/SKYRAD/C1 - Reprocess: IRT insufficiently heated

IRT had insufficient heating to maintain an internal reference temperature above 0 degrees 
C. Measurements of sky 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_down_long_hemisp_dome_temp or inst_down_long_dome_temp)

• IRT1 mean(irt1_mean)
• IRT1 minimum(irt1_min)
• IRT1 standard deviation(irt1_sd)
• IRT1 maximum(irt1_max)