STATISTICAL COMPARISON OF GLOBAL AND DIFFUSE SOLAR-RADIATION CORRELATIONS

Correlations for estimating monthly average daily global and diffuse radiation from sunshine data and global radiation data are developed using measured values of these parameters at Amritsar. The strength of the correlations has been confirmed from the values of coefficients of correlation and standard errors of estimate obtained thereof. The comparative study of our experimental results with the results obtained from other correlations reveals that, for estimating global radiation, the correlation suggested by Black et al. [Q. Jl R. met. Soc. 80, 231 (1954)] is most accurate, whereas for estimation of diffuse radiation, the relationship given by Page [Proc. U.N. Conf. on New Sources of Energy, Vol. 4, p. 378 (1961)] yields the most accurate results. © 1990.