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.

• Instantaneous Downwelling Pyrgeometer Thermopile, Unshaded Pyrgeometer(inst_down_long_hemisp_unshaded_tp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Unshaded
  Pyrgeometer(inst_down_long_unshaded_case_resist)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Unshaded
  Pyrgeometer(inst_down_long_unshaded_dome_resist)

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,
  Minima(down_short_diffuse_hemisp_min)
• 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, Standard
  Deviation(down_short_hemisp_std)
• Sky Infra-Red Temperature(sky_ir_temp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)

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

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.

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

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

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.

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

• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer1(inst_down_long_hemisp1_case_resist)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer2(inst_down_long_hemisp2_tp)
• Instantaneous Downwelling Pyrgeometer Thermopile, Pyrgeometer1(inst_down_long_hemisp1_tp)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer2(inst_down_long_hemisp2_dome_resist)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer2(inst_down_long_hemisp2_case_resist)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer1(inst_down_long_hemisp1_dome_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)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)
• 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)

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

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

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

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

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).

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

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

NSA/SKYRAD/C1 - Incorrect 20s dome thermistor data

The 30-second and 50-second PIR2 diffuse dome thermistor data
in all skyrad 20s data records taken to data is in fact case
thermistor data.  No other data are affected.  The 20 second
skyrad data cannot be used to recompute the diffuse PIR2 data.

Note: This data was named pir2_dome_therm at the beginning of
this time range andlater the variable was renamed to
inst_down_lng_shaded2_dome_resist.

• Instantaneous PIR2 dome thermistor(pir2_dome_therm)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded
  Pyrgeometer2(inst_down_long_shaded2_dome_resist)