DQRID : D980224.1
Start DateStart TimeEnd DateEnd Time Data Quality Metric
09/17/1997000010/03/19972359Suspect
more
Subject:
Reference Broadband Shortwave Data at SGP Central Cluster during Fall IOP '97
DataStreams:sgpbsrnC1.00, sgpbsrnC1.a0, sgpsirosE13.00, sgpsirosE13.a1, sgpbsrnC1.a1, sgpsirsE13.a1,
sgpsirsE13.a0
Description:
This is a recommendation for the best available broadband shortwave data from the SGP 
Central Cluster (Lamont, OK) during the Combined Fall IOP, 15 Sept - 5 Oct 1997.

Data available from the SGP Radiometer Calibration Facility (RCF) has lower measurement 
uncertainties than similar measurements from the C1, E-13, and BSRN/BRS platforms.

The RCF data were collected using the same Broadband Outdoor Radiometer CALibration 
(BORCAL) system used for routine calibration of pyranometers and pyrheliometers at the RCF.  
The data are available for 30-second interval.  
Direct normal irradiance measurements from a windowed RCF Absolute Cavity Radiometer 
during the IOP is considered more accurate (+/- 0.5%) than the Normal Incidence Pyrheliometers 
(NIP) at the Central Cluster (+/- 2%).
The Automated Hickey-Frieden cavity radiometer is electrically self-calibrating and 
provides reference standard data suitable for the calibration of the NIPs used at all the CART 
sites.

Diffuse horizontal irradiance is available as the average of two Eppley Precision Spectral 
Pyranometers and is considered slightly more accurate than the downwelling diffuse (DD) 
data from the Central Cluster instruments.
The RCF data will have periodic gaps during the electrical calibration intervals (about 
6-10 minutes, 4 or 5 times per day).
The reference global horizontal (or Downwelling Shortwave - DS) has been computed from the 
measured direct normal and diffuse components:
DS = NIP x Cos(Z) + DD,
where, Z = solar zenith angle.

All RCF data collected during the IOP are on the ARM IOP Web page 
(iop.archive.arm.gov/arm-iop). 
with other data from the Fall97 shortwave IOP.

Additional corrections to the diffuse data may be possible after researching PSP nighttime 
offsets.

Data from C1, E-13, and BSRN/BRS platforms during the SW-IOP '97 are still being 
investigated.
Suggestions: 
Use the RCF/BORCAL data files available during the Fall SW-IOP in place of the SIRS 

data from C1 and E-13 and the BSRN data for NIP, DD, and DS values.
This data set has been archived as sgprcfbbswiop97C1.00
Measurements:sgpsirsE13.a1:
  • down_short_diffuse_hemisp_min
  • down_short_hemisp_max
  • down_long_hemisp
  • up_short_hemisp_max
  • up_long_hemisp_min
  • down_short_diffuse_hemisp
  • short_direct_normal_std
  • up_long_hemisp_std
  • down_long_hemisp_max
  • up_long_hemisp
  • down_short_diffuse_hemisp_std
  • up_short_hemisp_min
  • down_long_hemisp_min
  • down_short_hemisp_std
  • up_short_hemisp_std
  • short_direct_normal
  • short_direct_normal_min
  • down_short_hemisp
  • short_direct_normal_max
  • down_long_hemisp_std
  • up_long_hemisp_max
  • up_short_hemisp
  • down_short_hemisp_min
  • down_short_diffuse_hemisp_max
more
sgpsirosE13.a1:
  • hemisp_narrowband
  • down_long_diffuse_hemisp
  • up_short_hemisp
  • down_long_case_temp
  • down_short_diffuse_hemisp
  • diffuse_hemisp_broadband
  • short_direct_normal
  • down_long_dome_temp
  • hemisp_broadband
  • direct_norm_narrowband
  • up_long_hemisp
  • direct_norm_broadband
  • down_short_hemisp
  • diffuse_hemisp_narrowband
more
sgpsirosE13.00:
  • Raw data stream - documentation not supported
more
sgpsirsE13.a0:
  • down_long_hemisp
  • down_short_hemisp
  • up_short_hemisp
  • short_diffuse
  • up_long_hemisp
more
sgpbsrnC1.a0:
  • spsp1
  • spsp2
  • nip
  • snip
  • psig
  • ssig
  • psp1
more
sgpbsrnC1.a1:
  • psig
  • psp2
  • psp1
  • nip
more
sgpbsrnC1.00:
  • Raw data stream - documentation not supported
more

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