Characterization of the angular response of a multi-directional spectroradiometer for measuring spectral radianceMario Tobar Foster, Eduardo Luiz Weide, Angelika Niedzwiedz, Jens Duffert and Gunther SeckmeyerEPJ Techn Instrum, 8 1 (2021) 12DOI: https://doi.org/10.1140/epjti/s40485-021-00069-4