## 3 Results and Discussion
### Minor Particle Position  
In the particle aggregate of Mode A, the positions of the minor component particles also influence the radiometric properties. Figure 5 provides spectrum-averaged radiometric properties of the particle aggregate with different position patterns of the minor component particles. The spectrum-averaged radiometric properties are averaged at wavelengths of 6.5-10 \(\upmu\)m. The particle aggregate of consideration has the same structure as that shown in Figure 2a, but it has nine different position patterns of minor component particles, including the minor component particles gathering in the up, down, left, right, front, and back of the aggregate as well as the randomly scattered particles. In the figure, Ran.1 is the average result of three different random position patterns, Ran.2 is the average result of six different random position patterns, and Ran.3 is the average result of nine different random position patterns. These three results agree well with each other, indicating that, as the minor component particles are randomly distributed, their positions have a small influence on the radiometric properties of the aggregate. In Figure 5, the minor component has a refractive index \(m_{2}=3.102+0.0925\)i and is more absorptive than the major component (\(m_{1}=1.6\)), as it has a larger imaginary part of the refractive index than the major component. As seen in the figure, the radiometric parameters of the random position pattern are quite different from those of the other patterns. The absorption efficiency with the random position pattern is greater than those with the other patterns (up, down, left, right, front, and back), as shown in Figure 5b. Considering that in the random pattern the minor component particles are distributed more evenly in the aggregate compared to other patterns, the greater absorption efficiency with the random position pattern shows that evenly spreading the minor component particle in the aggregate can increase the radiation absorption of the aggregate. For each absorptive minor component particle, the absorbed energy is proportional to the incident energy [53]. With a random pattern, the minor component particles are evenly distributed in the aggregate, and the incident radiation reaching a minor component particle is less shielded by other minor component particles,whereas, with other patterns in Figure 5, the minor component particles gather together, and before reaching a minor component particle the incident radiation may be well shielded by other minor component particles. Therefore, the average incident radiation energy for minor component particles with a random distribution is greater than that with other distributions in Figure 5, causing the absorbed energy by the aggregate with random patterns of minor component particles to be greater than that with other patterns. The scattering efficiency with the random position pattern is lower than that with other patterns, as shown in Figure 5c. This may be because of the greater absorption by the minor component particles in the aggregate with the random position pattern than that with other position patterns; thus, more radiation is absorbed and less is scattered. For the extinction efficiency (Figure 5a), the random pattern is similar to the other patterns compared to the absorption efficiency (Figure 5b) and scattering efficiency (Figure 5c). This is because the extinction efficiency is the sum of the absorption efficiency and the scattering efficiency, and the two different deviations of the random patterns from the other patterns in Figure 5b,c offset each other; as a result, the extinction efficiency of the random pattern becomes more close to the other patterns in Figure 5a.