Figure 5.

Example fish-eye photos taken to check for contamination of $E_d^{0+}$ measurements. (a) Contamination of field of view by other radiometers; (b) Contamination of field of view by a scientist in the bottom of the photo; (c) No contamination of field of view, partly cloudy sky; (d) No contamination of field of view, clear sky. The trees visible in the bottom-left photo, typical of inland water or very nearshore measurements, do affect the measurement, but are not considered as “contamination” in the context of this review. The impact of such far-field objects contributes to the natural downwelling irradiance at the measurement location, and should be measured as such.