## 2 Materials and Methods
### Experimental Data Sources and Collection  
The study conducted by [PERSON] et al. provides key findings that serve as a foundation for this research by systematically investigating the effects of automotive paints and environmental conditions on LIDAR performance. This study conducted a comprehensive analysis of the detectability of automotive paints with different colors and surface properties using intensity data obtained from LIDAR sensors. In the experimental setup, seven distinct automotive paint panels with matte black, gloss black, gloss white, gloss red, gloss blue, gloss silver, and gloss green finishes were employed. Each panel was further classified into metallic and non-metallic surfaces to examine the impact of surface composition on LIDAR reflectivity. Table 1 presents the colors and corresponding surface codes of the painted panels used in the tests [6].  
Figure 1: High-level block diagram for ToF LIDAR.  
The panels were coated using a manual spraying technique on flat, square nickel-plated mild steel plates. Each panel measured 50 cm \(\times\) 50 cm, and, for larger surface tests, four panels were combined to create a 1 m \(\times\) 1 m test surface. These dimensions were selected in accordance with physical constraints, and magnetic stabilizers were utilized to ensure precise panel positioning. During the experiments, the panels were oriented at different angles relative to the LIDAR sensor. Figure 2 illustrates the experimental setup used in this study, where a LiDAR sensor measures the reflectivity of test panels under controlled conditions. A customized mounting system ensures precise alignment and allows for systematic variation of panel angles between 0\({}^{\circ}\) and 70\({}^{\circ}\) in 5\({}^{\circ}\) increments. A digital angle gauge was used to ensure accurate angle adjustments. Additionally, reference surfaces, including matte black paper and a whiteboard, were incorporated to provide comparative reflectivity measurements. An alignment mirror was also utilized to maintain the sensor's alignment with the center of the panel, ensuring consistency in data collection [6].  
The Velodyne VLS-128 LIDAR (San Jose, CA, USA) sensor was utilized in this study. This sensor offers a detection range of up to 245 m with an accuracy of \(\pm\)3 cm. It provides a total vertical field of view (FoV) of 40\({}^{\circ}\), spanning from \(-\)25\({}^{\circ}\) to +15\({}^{\circ}\), with a fine vertical angular resolution of 0.11\({}^{\circ}\). Horizontally, it features a 360\({}^{\circ}\) FoV with an azimuthal angular resolution varying between 0.1\({}^{\circ}\) and 0.4\({}^{\circ}\). The device operates at a wavelength of 903 nm and emits 0.39 mW of power per laser, adhering to Class 1 laser safety standards. The Velodyne VLS-128 acquires approximately 2,400,000 data points per second in single rotation mode, while this capacity increases to 4,800,000 points in double rotation mode. In this study, the device was configured to operate in single rotation mode, capturing only the first return of the laser beams. This approach facilitated faster and more efficient data  
\begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Color** & **Surface Finish** & **Panel Code** \\ \hline
1 & White & Gloss & SW-Gloss \\ \hline
2 & Black & Gloss & SB-Gloss \\ \hline
3 & Black & Matte & SB-Matt \\ \hline
4 & Blue & Gloss & CDSBL-Gloss \\ \hline
5 & [PERSON] (Metallic) & Gloss & TCSRM-Gloss \\ \hline
6 & [PERSON] & Gloss & SMRTG-Gloss \\ \hline
7 & Silver (Metallic) & Gloss & TSSM-Gloss \\ \hline \end{tabular}
\end{table}
Table 1: SB/Standard black—black paint with standard black pigment.  
Figure 2: Experimental setup in this study: combined LiDAR test setup with a customized mounting system for test paint panels, including reference surfaces and alignment components [6].  
processing. During testing, the sensor was operated at a rotation rate of 10 Hz, ensuring reliable intensity measurements across different distances [20].