Streete, J. L. (1989). Calibration of the HAO Standard Opal Filter Set (No. NCAR/TN-340+STR). University Corporation for Atmospheric Research. doi:10.5065/D6WS8R59
This document describes the motivation for recalibrating the opal filters to know the transmittance values in spectral regions above and below those used in 1970. The spectral regions chosen were 450 nm, 550 nm, 650 nm and 800 nm. In summary, it is felt that the use of the direct radiation from t... Show moreThis document describes the motivation for recalibrating the opal filters to know the transmittance values in spectral regions above and below those used in 1970. The spectral regions chosen were 450 nm, 550 nm, 650 nm and 800 nm. In summary, it is felt that the use of the direct radiation from the sun, thereby insuring the proper geometry for the measurements, and employing a silicon photodiode detector,whose response is extremely linear over a wide dynamic range, have significantly improved the accuracy of the transmittance measurements. Show less
