SGP/BSRN/C1 - Reprocess: Adjust Direct Normal Irradiance

Direct normal broadband shortwave irradiance measured by NIP s/n 30721E6 was found to have 
a 4.1% negative bias when compared in-situ with absolute cavity radiometer measurements 
taken on August 21, 2000.  The estimated measurement uncertainty of the calibration of 
NIP s/n 30721E6 on July 18, 2000 was -2.8% to +3.5%.  The additional uncertainties of the 
field (rather than calibration) data acquisition system and installation contribute to the 
large negative bias found in the data on August 21, 2000.

Data from NIP s/n 30721E6 can be adjusted according to the in-situ comparisons to reduce 
the apparent measurement bias.

Multiply all direct normal irradiance measurements by 1.041.

• nip

• Raw data stream - documentation not supported

• nip