Bird Simple Spectral Model

THE MODEL

The Bird Simple Spectral Model, authored by Dr. Richard Bird and Dr. Carol Riordan, computes clear sky spectral direct beam, hemispherical diffuse, and hemispherical total irradiances on a prescribed receiver plane - tilted or horizontal - at a single point in time. For tilted planes, the user specifies the incidence angle of the direct beam (FORTRAN version) or the tilt and azimuth of the plane (Excel@ and C versions). The wavelength spacing is irregular, covering 122 wavelengths from 305 nm to 4000 nm. Aerosol optical depth, total precipitable water vapor (cm), and equivalent ozone depth (cm) must be specified by the user. No variations in atmospheric constituents or structure are available. There is no separate computation of circumsolar radiation. The direct beam spectral irradiance is assumed to contain the circumsolar radiation within a 5° solid angle. No smoothing functions are provided.




REFERENCES




DOWNLOAD THE MODEL

Three versions of the model are available on the RReDC:




SUGGESTED SOURCES FOR MODEL INPUT PARAMETERS:

Suggested links for most difficult to find input data (Aerosol Optical Depth Precipitable Water Vapor, Ozone) for Spectral modeling:




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