## 3 Results and Discussion
### Correction Functions for LISST-VSF
Figure 4: Correction functions, CF(\(\psi\)), for the LISST-VSF measurements of particulate volume scattering function \(\beta_{p}^{LISST*}(\psi)\) over the angular range 4.96–150\({}^{\circ}\) determined for 100, 200, and 400 nm polystyrene bead suspensions. For each individual bead size, dashed lines represent the median values and the dotted lines indicate the 25 th and 75 th percentiles determined from the series of measurements. The final computed correction function \(CF_{f}(\psi)\) is shown in black, and includes the constant value used for the near-forward angular range from 0.09\({}^{\circ}\) to 4.96\({}^{\circ}\). The comparisons of \(\beta_{p}^{\textit{LISST}}(\psi)\) and \(\beta_{p}^{\textit{REF}}(\psi)\) are shown in Figure 6 for the six polystyrene bead samples. The presented values of \(\beta_{p}^{\textit{LISST}}(\psi)\) are the median values for each angle from each measurement series. The measured values of \(\beta_{p}^{\textit{DAWN}}(\psi)\) are additionally depicted for the 100, 200, 400, and 700 nm diameter beads. In general, the magnitude and angular dependence of \(\beta_{p}^{\textit{LISST}}(\psi)\) exhibits good agreement with reference values for all bead diameters. Notable differences occur within the minima of volume scattering function, for example near the angle of \(80^{\circ}\) for the 400 nm beads (Figure 6c). This issue has been mentioned above in the context of determinations of \(CF_{f}(\psi)\) and \(BF_{f}(\psi)\). The agreement observed between \(\beta_{p}^{\textit{LISST}}(\psi)\) and \(\beta_{p}^{\textit{DAWN}}(\psi)\) lends additional credence to the determined correction function \(CF_{f}(\psi)\) and its application to LISST-VSF measurements. Figure 7a illustrates the relationship between \(\beta_{p}^{\textit{LISST}}(\psi)\) measured at all angles between \(3.02^{\circ}\) and \(150^{\circ}\) and \(\beta_{p}^{\textit{REF}}(\psi)\) for the corresponding angles for the six bead samples. The overall agreement is quite good over a range spanning nearly 4 orders of magnitude. The regions of largest disagreement correspond to angles measured with the ring detectors, as well as angles corresponding to sharp minima or maxima in volume scattering function which are observed for the larger beads. Although the measured minima and maxima occur essentially at the same angles as predicted by Mie scattering calculations, the measured magnitude of minima or maxima can differ by a few tens of percent from the reference values. This is illustrated by plots of percent differences between the measured and reference values (Figure 7b). The oscillations and peaks (both positive and negative) in percent differences correspond to the minima and maxima in the angular patterns of volume scattering function. Figure 5: Correction functions, \(BF(\psi)\), for LISST-VSF measurements of the degree of linear polarization of light scattered by particles, \(DoLP_{p}^{\textit{LISST}*}(\psi)\) over the angular range 16–150\({}^{\circ}\) determined for 100, 200, and 400 nm polystyrene bead suspensions. For each individual bead size, dashed lines represent the median values and the dotted lines indicate the 25 th and 75 th percentiles determined from the series of measurements. The final computed correction function \(BF_{f}(\psi)\) is shown in black. Table 2 includes several statistical parameters that quantify the agreement between the data of \(\beta_{p}^{LISST}(\psi)\) and \(\beta_{p}^{REF}(\psi)\) illustrated in Figure 7a. In this analysis we ignore \(\psi\) < 3.02\({}^{\circ}\) due to generally low scattering signal relative to baseline for these ring detectors. The values of statistical parameters support the overall good agreement; for example, the median ratio (\(MR\)) of \(\beta_{p}^{LISST}(\psi)\) to \(\beta_{p}^{REF}(\psi)\) is very close to 1, and the median absolute percent difference (\(MAPD\)) between \(\beta_{p}^{LISST}(\psi)\) and \(\beta_{p}^{REF}(\psi)\) is only ~4%.