Premium
Influence of Sampling Frequency on the Precision of Estimating Accumulated Solar Radiation 1
Author(s) -
Holt D. A.,
Youngberg H. W.
Publication year - 1971
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1971.00021962006300020013x
Subject(s) - pyranometer , sampling interval , radiation , integrator , intensity (physics) , standard deviation , statistics , interval (graph theory) , mathematics , zoology , environmental science , accuracy and precision , variable (mathematics) , confidence interval , atmospheric sciences , optics , physics , biology , voltage , mathematical analysis , quantum mechanics , combinatorics
Instantaueous solar radiation intensity measurements were recorded at various time intervals. These were numerically integrated over individual days and the accumulation estimates thus obtained were compared to daily totals read from an integrating device operating continuously on the same Eppley pyranometer. Precision of daily accumulated radiation estimates decreased as time interval between intensity measurements increased. In the entire sample of 100 days, the standard deviations of differences between integrator values and calculated estimates increased about 0.5 Langley per additional minute in interval between measurments. Precision loss with increase in time interval was greater on variable days than on consistent days and about the same on bright and dull days. Precision was greater and decreased less with time interval on dull, consistent days than on dull, variable days and on bright, consistent rather than bright, variable days.