SGP/SIRS/E24 - NIP shaded near sunrise

The NIP is shaded by the EF laptop computer enclosure near sunrise during parts of the 
Spring and Summer.  This has occurred from 04/08 to 05/20 and from 07/26 to 09/06 every year 
since 2001 and will occur during these date ranges in the future as well.  The shading 
occurs for a few minutes each day between 1200 and 1300 GMT depending on the time of the 
year.  For the early dates, shading occurs a little after 1200 GMT and by 05/20 shading 
happens nearer to 1300 GMT. In late July the shading occurs near 1300 GMT and closer to 
1200 GMT by 09/06.

• Instantaneous Direct Normal Shortwave Irradiance, Pyrheliometer Thermopile
  Voltage(inst_direct_normal)

• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrheliometer(short_direct_normal)

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(Raw data stream - documentation not supported)

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

• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyrgeometer, Standard
  Deviation(down_short_hemisp_std)

SGP/SIRS/E24 - Reprocess: Incorrect calibration coefficients

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(Raw data stream - documentation not supported)

• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)

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

SGP/SIRS/E24 - Reprocess: Incorrect calibration coefficients

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(Raw data stream - documentation not supported)

• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)

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

SGP/SIRS/E24 - 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.

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)