NSA/SKYRAD/C1 - Preventive maintenance

Preventive maintenance to rebuild ventilator fan and exchange instruments during this time 
removed Skyrad instruments from operation.  Most data collected are not scientifically 
relevant.

• down_long_hemisp_shaded2_std
• down_long_hemisp_unshaded_std
• psps_mean
• psps_min
• down_long_hemisp_shaded2_max
• pirs_mean
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• uvb_mean
• nip_min
• down_long_hemisp_shaded1_max
• pirs_min
• pir1_sd
• short_direct_normal_std
• pirs_max
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• psps_sd
• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer, Minima(down_long_hemisp_unshaded_min)
• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer, Maxima(down_long_hemisp_unshaded_max)
• psp1_min
• psp1_max
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• down_short_diffuse_hemisp_std
• pir1_mean
• psp1_mean
• nip_max
• Downwelling Ultra-Violet Irradiance, UV Biometer(down_uvb)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• uvb_min
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• down_uvb_std
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• external_voltage
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• nip_mean
• Downwelling Ultra-Violet Irradiance, UV Biometer, Maxima(down_uvb_max)
• uvb_sd
• down_short_hemisp_std
• uvb_max
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer1(down_long_hemisp_shaded1)
• pirs_sd
• Irradiance, longwave, downwelling, hemispheric, shaded pyrgeometer2(down_long_hemisp_shaded2)
• psp1_sd
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• filename
• Downwelling Longwave Hemispheric Irrad., Shaded Ventilated Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• down_long_hemisp_shaded2_min
• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer(down_long_hemisp_unshaded)
• nip_sd
• pir1_min
• Downwelling Ultra-Violet Irradiance, UV Biometer, Minima(down_uvb_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Ventilated Pyrgeometer(down_long_hemisp_shaded)
• down_long_hemisp_shaded_std
• psps_max
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• pir1_max
• down_long_hemisp_shaded1_std
• down_long_hemisp_shaded1_min

• inst_down_long_shaded1_case_resist
• inst_down_long_shaded1_dome_resist
• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer2)(inst_down_long_hemisp_shaded2_tp)
• inst_down_long_shaded2_dome_resist
• inst_down_long_shaded2_case_resist
• inst_diffuse
• inst_direct_normal
• Irradiance, longwave, downwelling, hemispheric, thermopile (Shaded Pyrgeometer1)(inst_down_long_hemisp_shaded1_tp)
• inst_global

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/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.

• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• 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)

• 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 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/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.

• inst_down_long_hemisp2_tp
• inst_down_long_hemisp2_case_temp
• inst_down_long_hemisp1_dome_temp
• down_long_hemisp2_min
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer1(down_long_hemisp1)
• down_long_hemisp2_max
• down_long_hemisp2_std
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer2(down_long_hemisp2)
• inst_down_long_hemisp1_case_temp
• down_long_hemisp1_min
• inst_down_long_hemisp1_tp
• down_long_hemisp1_std
• inst_down_long_hemisp2_dome_temp
• down_long_hemisp1_max

• inst_down_long_hemisp1_dome_resist
• inst_down_long_hemisp2_tp
• inst_down_long_hemisp2_case_resist
• inst_down_long_hemisp2_dome_resist
• inst_down_long_hemisp1_tp
• 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_ir_temp_min
• sky_ir_temp_std
• sky_ir_temp_max
• Temperature, Sky Infra-Red(sky_ir_temp)

• inst_sky_ir_signal