Fig. 8: Comparison of scattering functions.
From: Direct observations of negative ions on the Lunar surface by Chang'E-6

One dimensional slices of the scattering functions for the average NILS solar zenith and azimuth angles, in the direction ϕ = 215° where NILS is the most sensitive are shown. The radial scale of the NILS angular response function \({{{{\mathcal{R}}}}}_{\Omega }\) indicates how sensitive the instrument is in different directions (in arbitrary units).