Characterization of the angular response of a multi-directional spectroradiometer for measuring spectral radiance

Abstract Despite its importance, few instruments are able to measure the angular distribution of solar spectrum with a high spectral and temporal resolution. We present novel characterization method multi-directional entrance optics AMUDIS (Advanced MUltiDIrectional Spectroradiometer) which is multidirectional spectroradiometer based on three CCD image sensors combined imaging spectrographs. The new type consists 435 different optical fibres uniformly distributed along 145 directions covering upper hemisphere allowing simultaneous measurements radiance in ultraviolet, visible near infrared part spectrum, ranging from 280 nm 1700 nm. experimental setup for characterizing 100 W halogen lamp robotic arm, moves tangentially over surface virtual sphere 102.5 cm radius around optics. revealed misalignments position up 3 ∘ (which can affect measurements, specially under broken clouds conditions). improved 3-fold alignment ±0.1