SunScan User Manual v 1.05
Technical Reference section
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73
Cosine responses of probe and BFS
The cosine response curves show a diminishing response compared to the ideal at
high zenith angles. For this reason, you should avoid taking measurements when the
sun is strong and near the horizon.
Most studies will be looking at the ratio of incident and transmitted light, and the
graph shows the SunScan and Beam Fraction sensor are very closely matched in
their cosine and spectral responses, so the small deviations from the ideal will not
introduce significant errors.
SunScan system cosine response
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
0 10 20 30 40 50 60 70 80 90 0 10 20 30 40 50 60 70 80 90
SunScan probe Zenith angle ° Beam Fraction sensor
relative response
Ideal
Actual
Actual / Ideal
