esa-sceva/satcom-chunk-collection huggingface dataset:
# Dual-Polarized Multi-Beam Fixed-Frequency Beam Scanning Leaky-Wave Antenna
## 3 Results and Discussion
Because the parasitic resistance of the varactor diode has a large impact on the radiation efficiency of the antenna, so we take the first group of the dual-polarized antenna as an example and change the parasitic resistance value to observe the corresponding variation in radiation efficiency; the results are displayed in Figure 11. Without considering the effect of device parasitic resistance, the radiation efficiency of the dual-polarized antenna is higher than 75%. The parasitic resistance of the device will cause the radiation efficiency of the active antenna to decrease. It can be seen that Y-polarized antennas are less affected by the parasitic resistance because the number of loaded varactor diodes is less, so when the parasitic resistance of the device is 2 \(\Omega\), the radiation efficiency of more than 56% can still be achieved in the operating frequency band. However, the X-polarized antennas suffer from a higher Ohmic loss during simulation, which is because the X-polarized antenna uses a larger number of active devices. The measurement results show that the actual radiation efficiency of the dual-polarized antenna exceeds 60% in the frequency range of 3.3 to 3.8 GHz. Figure 10: Measured radiation patterns for excitation of different feeding ports. X-polarized antenna in (**a**) multi-beam operating state, (**b**) single-beam operating state; Y-polarized antenna (**c**) multi-beam operating state, (**d**) single-beam operating state. Figure 9: Measured normalized radiation patterns with different bias voltages loaded at 3.5 GHz. (**a**) antenna 1, (**b**) antenna 2, (**c**) antenna 3, (**d**) antenna 4. Table 2 provides a comparison of performances between the proposed dual-polarized multi-beam fixed-frequency beam scanning LWA and the previously reported LWAs. In Table 2, \(\lambda_{0}\) is the wavelength at the center frequency of the working band for LWAs. Although these previous works have achieved fixed-frequency beam scanning, most of them are single-polarized and can only form a single beam. The proposed antenna is dual-polarized and can form multiple beams, while the beam width can be flexibly adjusted by switching between multi-beam and single-beam states. The proposed antenna also performs well in terms of gain and beam scanning range.
# FTIR Characterization of Asphalt SARA Fractions in Response to Rubber Modification
## 3 Results and Discussion
### Rheological Analysis of Asphalt Matrix  
Figure 9 illustrates the variations of \(G^{*}\) and \(\delta\) with respect to temperatures for neat binder and A-RBs. The COV values for \(G^{*}\) varied from 0.00 to 9.09%, whereas those for \(\delta\) ranged from 0.00 to 1.89%. The \(G^{*}\) values in Figure 9a for the A-RBs were higher than those of the neat binder, while the neat binder exhibited the highest \(\delta\) values (Figure 9b), demonstrating that A-RBs had the highest stiffness and elasticity values. Among A-RBs, the sample that interacted at 190-3000 had the highest stiffness and elasticity values, revealing more effective rubber swelling and partial dissolution. The mechanism of interaction between rubber and asphalt caused network structure formation, as revealed in a previous study [32], enhancing the viscoelastic properties. Furthermore, the plateau region in the \(\delta\) curve [57; 58], as shown in Figure 9b, particularly for A-RB 190-3000, revealed the formation of network structures. The 600 min\({}^{-1}\) interaction speed was not sufficient to release the rubber components in the asphalt matrix, as confirmed by the results discussed in Figure 7 and the rubber dissolution results revealed in the upcoming section, causing the lowest enhancements in the rheological properties compared to other A-RBs. Increasing the interaction temperature from 190 to 220 \({}^{\circ}\)C reduced the \(G^{*}\) and increased the \(\delta\) values due to excessive devulcanization and depolymerization of the rubber components. The \(\delta\) value consistently high for the neat binder above 40 \({}^{\circ}\)C, indicated that the neat binder was behaving mostly in a viscous manner, with little elastic contribution. In contrast, the steadily increasing \(\delta\) of the A-RBs indicated that temperature was causing softening and slow degradation of the rubber-reinforced elastic network within the binder matrix as a result of temperature [59]. Chemical changes in the SARA fractions were linked to rheological enhancements, including higher \(G^{*}\) and lower \(\delta\). Asphalt-rubber interactions reduced the amount of saturates and aromatics while increasing the amount of resins and asphaltenes. Additionally, the polymeric components released from rubber into the asphalt liquid phase were observed for the sample interacted at 190 \({}^{\circ}\)C and 3000 min\({}^{-1}\), providing higher \(G^{*}\) and lower \(\delta\) values.
## 2 Classical ANC Algorithms  
### Classical ExLMS Algorithm  
A block diagram of a single-channel ANC system [3] for duct applications is illustrated in Figure 1, where \(P(z)\) denotes the primary path present between the noise source generating \(x(n)\) and the location of the error microphone. Here, \(S(z)\) is the secondary acoustic path present between the loudspeaker and the error microphone. As shown in Figure 1, the noise source is assumed to be of impulsive nature, further described while discussing the simulation results presented later. The reference signal \(x(n)\) is propagated via \(P(z)\) and appears as the disturbance \(d(n)\) around the location of the error microphone.  
Assuming that the ANC filter \(w(n)\xleftarrow{z}\)\(W(z)\) (having impulse response \(w(n)\)) is a finite impulse-response (FIR) filter of coefficient length \(L\), the corresponding ANC filter output signal \(y(n)\) can be expressed as  
\[y(n) =w(n)*x(n),\] \[=\mathbf{w}^{T}(n)\mathbf{x}(n), \tag{1}\]  
where \(\mathbf{w}(n)=[w_{0}(n),w_{1}(n),\ldots,w_{L-1}(n)]^{T}\) and \(\mathbf{x}(n)=[x(n),x(n-1),\ldots,x(n-L+1)]^{T}\) are the coefficient vector for \(W(z)\) and the corresponding reference signal vector, respectively, and \(T\) and \(*\) denote transposition and convolution, respectively. The ANC filter output signal \(y(n)\) is filtered via \(S(z)\) to give the cancellation signal \(y^{\prime}(n)\) which is acoustically combined with \(d(n)\) to generate the residual error signal \(e(n)\) being expressed as  
\[e(n) =d(n)-y^{\prime}(n)\] \[=d(n)-s(n)*y(n)\] \[=d(n)-s(n)*w(n)*x(n). \tag{2}\]  
It is important to mention that neither the disturbance signal \(d(n)\) nor the cancelling signal \(y^{\prime}(n)\) are directly accessible; \(y(n)\) is generated from the ANC filter and then only \(e(n)\) is picked-up by the error microphone. Assuming slow adaptation of the ANC filter \(W(z)\) allows rearranging the convolutions in (2) and re-writing the expression for \(e(n)\) as  
\[e(n) =d(n)-w(n)*x_{f}(n),\] \[=d(n)-\mathbf{w}^{T}(n)\mathbf{x}_{f}(n), \tag{3}\]  
Figure 1: Block diagram of a filtered-x (Fx) LMS-based ANC structure.  
where \(\mathbf{x}_{f}(n)=[x_{f}(n),x_{f}(n-1),\ldots,x_{f}(n-L+1)]^{T}\) is the Fx signal vector where \(x_{f}(n)=s(n)*x(n)\). The the classical FxLMS algorithm is based on minimizing the mean-squared-error (MSE)  
\[\xi_{\text{MSE}}(n)=\mathbb{E}\{e^{2}(n)\}\approx e^{2}(n), \tag{4}\]  
which results in the following updated equation for the FxLMS algorithm [3,4]  
\[\mathbf{w}(n+1)=\mathbf{w}(n)+\mu e(n)\mathbf{x}_{f}(n), \tag{5}\]  
where \(\mu\) is a FSS parameter. In (3) and (5), the Fx signal \(x_{f}(n)\) can be computed using the secondary path modeling filter \(\hat{s}(n)\xleftarrow{z}\hat{s}(z)\) as \(x_{f}(n)=\hat{s}(n)*x(n)\) (see Figure 1).
# Positron Emission Tomography in Coronary Heart Disease
## 3 Perfusion Imaging
### Imaging Myocardial Perfusion with Rubidium-82 (Rb)  
Rb myocardial uptake is proportional to MBF, as was demonstrated for the first time more than half a century ago [34]. It is the most widespread tracer used for PET myocardial perfusion imaging (MPI), since it does not require a cyclotron on-site. It has a half-life of 78 s and an extraction fraction in comparison to MBF of around 60% [35].  
Compared with conventional MPI with SPECT, Rb-PET showed improved image quality, higher diagnostic accuracy, less radiation dose to patient and staff as well as rapid examinations time [36]. It has also shown better sensitivity for the detection of multivessel disease, which in cases of balanced ischemia may present as a false negative in SPECT [35]. A recent meta-analysis compared the diagnostic performance of cardiac magnetic resonance (CMR), SPECT, and PET imaging for the identification of CAD and concluded that both CMR and PET were superior to SPECT [37]. However, a randomized study comparing the clinical effectiveness of pharmacologic SPECT and PET MPI in symptomatic CAD patients (\(n=322\)) showed no significant differences between the two groups in subsequent rates of coronary angiography, coronary revascularization, or health status at 3-, 6-, and 12-month follow-ups [38].  
In a cohort of 16,029 consecutive patients undergoing Rb rest-stress PET MPI, patients with higher degrees of ischemia had a survival benefit from early revascularization [39].
## 4 Electrical Modeling Results
### Electrical Modeling Procedure
According to the calculation results in Table 1, the improvement percentages of \(\mathrm{J_{SC}}\) in the surface-textured CIGS solar cell without the front encapsulation layers are 9.31%, 9.17%, 8.55%, and 6.38% at the AM 1.5 sunlight incidence angle of \(0^{\circ}\), \(30^{\circ}\), \(45^{\circ}\), and \(60^{\circ}\), respectively. On the other hand, the improvement percentages of \(\mathrm{J_{SC}}\) in the surface-textured CIGS solar cell with the front encapsulation layers are 5.58%, 5.74%, 5.76%, and 5.51% at the same incidence angle. Thus, the absorption enhancement of the surface-textured CIGS solar cell over the planar CIGS solar cell can be over-predicted when the thick encapsulation layers are not considered in the numerical calculation. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Incidence** & \begin{tabular}{c} **Planar CIGS Solar Cell** \\ **without the Front** \\ **Encapsulation Layer** \\ \end{tabular} & \begin{tabular}{c} **Surface-Textured CIGS Solar** \\ **Cell without the Front** \\ **Encapsulation Layer** \\ \end{tabular} & \
\begin{tabular}{c} **Planar CIGS Solar Cell** \\ **with the Front** \\ **Encapsulation Layer** \\ \end{tabular} &
\begin{tabular}{c} **Surface-Textured CIGS Solar** \\ **with the Front** \\ **Encapsulation Layer** \\ \end{tabular} \\ \hline \(0^{\circ}\) & \(-33.83\) & \(-36.98\) (9.31\%) & \(-34.05\) & \(-35.95\) (5.58\%) \\ \(30^{\circ}\) & \(-29.11\) & \(-31.78\) (9.17\%) & \(-29.42\) & \(-31.11\) (5.74\%) \\ \(45^{\circ}\) & \(-23.40\) & \(-25.40\) (8.55\%) & \(-23.79\) & \(-25.16\) (5.76\%) \\ \(60^{\circ}\) & \(-15.68\) & \(-16.68\) (6.38\%) & \(-16.14\) & \(-17.03\) (5.51\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Calculated short-circuit current density (\(\mathrm{J_{SC}}\)) of the planar and surface-textured CIGS solar cells without and with the inclusion of the front encapsulation layers, which are taken from Figure 11. The unit of \(\mathrm{J_{SC}}\) is mA/cm\({}^{2}\). The improvement percentage of \(\mathrm{J_{SC}}\) in the surface-textured CIGS solar cell over the planar CIGS solar cell is denoted in the parenthesis whether the front incoherent encapsulation layers are included or not.
# Development of Dual-Axis MEMS Accelerometers for Machine Tools Vibration Monitoring
## 2 Development of Dual-Axis Micro Electro Mechanical Systems (MEMS) Accelerometers
### Housing and Fixed Magnetic Structure  
The housing design should be small, lightweight, and structurally rigid. Moreover, the sensitive axis of the ADXL001 accelerometer is perpendicular to the surface of the spindle. Therefore, we utilized AL7075 materials to design housing that was internally rectangular but externally cylindrical (\(\varphi\)20 mm \(\times\) H30 mm). The geometric design and dimension of the accelerometer housing are shown in Figure 3a. In the process of assembly, the ADXL001 was attached on each side of the rectangular structure, which is sensitive to vibration on both the \(x\)- and \(y\)-axes, as shown in Figure 3b.  
The fixed condition between the accelerometer and the machine affects the effective frequency range of measurement. For close adhesion with the machine, we utilized a magnetic structure on the bottom of the housing, as shown in Figure 3c.
## 3 Nutraceuticals
### Diabetic Retinopathy and Nutraceuticals (Cocoa) Treatment  
Diabetes treatment consists of both pharmacological treatments and dietary adjustments. In this respect, whether diabetic retinopathy can be prevented or treated in diabetic patients through dietary changes has not been well examined; so, further research in this area is required [86]. Currently available DR treatment comprises of glycemic control, among other things, with active treatment starting only in advanced stages of the disease [12]. Nutrition, in addition to therapeutic intervention in diabetes therapy, plays an important role in both diabetes prevention and control. Carbohydrates, fatty acids, monounsaturated and polyunsaturated fatty acids, and vitamins are among the macronutrients involved in diabetes control [87].  
Eating foods like fish, fruits, and vegetables may also protect against the onset and progression of DR. Cheese, for example, is estimated to have the capacity to slow DR progression by 40% [87]. Nutraceuticals such as carotenoids, xanthophyll, lutein, and zeaxanthin improve retinal health and function in retinal diseases while also protecting against hyperglycemia-induced vascular changes in diabetes [22]. Lutein supplementation, in particular, may be effective in preventing oxidative stress-induced retinal damage and slowing the progression of DR [21]. In addition to these nutraceuticals, flavonoids increase insulin sensitivity, carbohydrate and lipid metabolism, beta cell function, and hypoglycemia. Importantly, flavonoids have been shown to help lower the progression of diabetes and the development of diabetes complications, including DR [7].  
Indeed, flavonoids (found in a variety of fruits, vegetables, and cocoa products) offer a promising alternative treatment for diabetes mellitus due to their plentiful antioxidant capabilities (higher phenolic compounds) [71]. These nutraceuticals' mechanisms for improving diabetes and retinal function include, but are not limited to, increasing insulin sensitivity, lowering blood pressure and inflammatory processes, and preventing platelet activation and aggregation [71; 88]. It would be excellent to examine the preventive effects of cocoa (flavanol nutraceutical) against hyperglycemia-induced retinal dysfunctions in adult Sprague Dawley rats in order to better understand the mechanisms involved in the development and advanced state of diabetic retinopathy.
# Nascent Rice Husk as an Adsorbent for Removing Cationic Dyes from Textile Wastewater
## 3 Results and Discussion
### Influence of solution pH  
The adsorption of MB and CV onto RH (Figure 6), is presented concerning solution pH as the pH increased from 4 to 10. The removal percentages of MB and CV all exceeded 95 % at the pH range of 4-10. The adsorption capacity of molecules of both, MB and CV, increased as pH increased from 4 to 10, even though the increase was insignificant. The adsorption efficiency is dependent on the solution pH, as variation in pH affects the degree of ionization of adsorptive molecules and the adsorbent surface properties [91]. MB and CV are cationic dyes that exist in an aqueous solution as positively charged ions. Consequently, for charged molecules, the degree of adsorption of these cations onto the surface of the RH could be primarily impacted by the surface charge of the adsorbent, which is dependent on the solution pH. The point of zero charge (pHpzc) of unmodified RH has a value of 2.7 [92]; when the solution pH > pHpzc, the surface of the adsorbent is negatively charged, with more functional groups available for bonding (attributed to deprotonation). In this experimental condition (pH > 4), there was an electrostatic interaction between positively charged dyes and the negatively charged surface of RH particles, prompting favorable adsorption but the electrostatic repulsion between anionic dyes and RH surfaces. This can alternatively be explained by other adsorption methods, e.g., ion exchange, which is consistent with other studies [93].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Adsorbate**} & **Temperature** & \(\Delta\)H\({}^{\circ}\) & \(\Delta\)S\({}^{\circ}\) & \(\Delta\)G\({}^{\circ}\) \\  & **(K)** & **(kJ/mol)** & **(J/mol K)** & **(kJ/mol)** \\ \hline \multirow{3}{*}{MB} & 288 & & & \(-\)1.1115 \\  & 298 & 28.50 & 0.103 & \(-\)1.9774 \\  & 308 & & & \(-\)3.1703 \\ \hline \multirow{3}{*}{CV} & 288 & & & \(-\)2.7018 \\  & 298 & 151.53 & 0.535 & \(-\)7.6901 \\  & 308 & & & \(-\)13.4146 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Thermodynamic parameters for adsorption of methylene blue (MB) and crystal violet (CV) on rice husk. \(\Delta\)H\({}^{\circ}\): the change in enthalpy (kJ/mol); \(\Delta\)S\({}^{\circ}\): the change in entropy (J/mol K); \(\Delta\)G\({}^{\circ}\): the change in Gibb’s free energy (kJ/mol).
## 1 Introduction  
Widely tunable mid-infrared radiation source operating in 3-5 \(\upmu\)m region has been applied to numerous frontier applications, including remote sensing, molecular spectroscopy and atmosphere environmental monitoring [1; 2; 3]. OPOs pumped by a Q-switched laser are commonly used in high energy, widely tunable mid-infrared pulse generation. The nonlinear crystal is of great significance to the output performance OPO. Non-oxide crystals usually have a wider transparent range than oxide crystals which have unneglectable multi-phonon absorption over 4 \(\upmu\)m [4]. Therefore, non-oxide crystals have advantages in mid-infrared wave generation especially in the range over 4 \(\upmu\)m. Due to the defects from the grown process and the limit of the bandgap, the transmittance in visible to near-infrared range of some non-oxide crystals is relatively low. It leads to a limitation on the pump wavelength of non-oxide crystal-based OPOs. Non-oxide crystals used for 1 \(\upmu\)m laser pumped OPOs are of great interest, including AgGaS\({}_{2}\)[5], HgGa\({}_{2}\)S\({}_{4}\)[6], LiInSe\({}_{2}\)[7], LiGaS\({}_{2}\)[8], BaGa\({}_{4}\)S\({}_{7}\)[9], and CdSiP\({}_{2}\)[10]. High-quality non-oxide crystals which can be used for a commercial 1 \(\upmu\)m laser pumped OPO are still urgently needed.  
The newly developed mid-infrared crystal BaGa\({}_{4}\)Se\({}_{7}\) (BGSe) exhibits a wide bandgap (2.64 eV), wide transparent range (0.47-18 \(\upmu\)m) and high laser damage threshold (557 MW/cm\({}^{2}\)), which is beneficial for OPOs pumped by an economical 1064 nm laser [11]. Generation of high energy mid-infrared laser has been reported in both 3-5 \(\upmu\)m mid-wave mid-infrared [12; 13; 14] and 8-14 \(\upmu\)m long-wave mid-infrared range [14; 15; 16]. The maximum energy of 21.5 mJ/pulse has been reported using a large-size BGSe of 10 \(\times\) 10 \(\times\) 16 mm\({}^{3}\)[17]. However, due to the relatively low thermal conductivity [18] and the increasing damage probability under high repetition rate laser pumping [19; 20; 21], reports on the high average power BGSe-OPO pumped with 1064 nm laser are rare.  
In this paper, we demonstrated a widely tunable BGSe optical parametric oscillator with a repetition rate up to 250 Hz. Pumped by a side-pumped Q-switched Nd:YAG laser, the BGSe-OPO reached a maximum output average power of 250 mW at 4.06 \(\upmu\)m and an optical-to-optical conversion efficiency of 11.1%, which is the highest in the current results regarding 1064 nm laser pumped high repetition rate mid-infrared source based on BGSe crystal. Using a pump double-pass configuration, the OPO threshold was reduced to 2.65 mJ/ pulse with a cavity length of 30 mm. Tunable mid-infrared output from 3.42 \(\upmu\)m to 4.73 \(\upmu\)m is achieved by changing the critical phase-matching condition. The pulse width of the generated mid-infrared wave was measured to be 13.6 ns and the linewidth at 4061 nm is estimated to be 3.92 nm.
## 3 Research of the Path Tracking Control Strategy
### Global Stability Analysis of Closed Loop Controller  
Due to the existence of a deviation between the actual driving direction angle \(\theta\) and the ideal driving direction angle \(\theta_{d}\) in the initial stage of control, the kinematic model (12) can be written as follows:  
\[\left\{\begin{array}{l}\dot{x}=v\cos\alpha_{d}+v(\cos\alpha-\cos\alpha_{d}) \\ \dot{y}=v\sin\alpha_{d}+v(\sin\alpha-\sin\alpha_{d})\\ \dot{\theta}=w\end{array}\right. \tag{24}\]  
Then, Equation (18) can be written as follows:  
\[\left\{\begin{array}{l}\dot{x_{e}}=-p\text{tanh}(g_{1}x_{e})+v(\cos\theta- \cos\theta_{d})\\ \dot{y_{e}}=-q\text{tanh}(g_{2}y_{e})+v(\sin\theta-\sin\theta_{d})\end{array}\right. \tag{25}\]The certification process when \(t\to\infty\), \(x_{e}\to 0\) is as follows:  
Select the Lyapunov function as  
\[V=pln(\cosh g_{1}x_{e})+\frac{1}{2}g_{1}x_{e}{}^{2}\]  
Derivation of the above Lyapunov function can obtained as follows:  
\[\dot{V}=pg_{1}\dot{x_{e}}\text{tanh}(g_{1}x_{e})+g_{1}x_{e}\ddot{x_{e}} \tag{26}\]  
Take \(n_{1}=p\text{tanh}(g_{1}x_{e})\), \(n_{2}=v(\cos\alpha-\cos\alpha_{d})\).  
Then  
\[x_{e}=n_{1}+n_{2}\]  
Equation (26) can be written as follows:  
\[\dot{V}=-g_{1}(n_{1}-\frac{1}{2}n_{2})^{2}-pg_{1}x_{e}\text{tanh}(g_{1}x_{e})+ \frac{1}{4}g_{1}n_{2}(n_{2}+4x_{e})\]  
From the nature of the sine function \(\left|\cos\theta-\cos\theta_{d}\right|=\left|2\sin\frac{\theta+\theta_{d}}{2} \sin\frac{\theta-\theta_{d}}{2}\right|\leq 2\left|\sin\frac{\theta-\theta_{d}}{2} \right|\leq 2\left|\frac{\theta-\theta_{d}}{2}\right|\), when \(\theta-\theta_{d}\) converges, \(\left|\cos\theta-\cos\theta_{d}\right|\) converges, which is followed by the converge of \(n_{2}\).  
Since \(pg_{1}x_{e}\text{tanh}(g_{1}x_{e})\geq 0\):  
\[\dot{V}\leq-g_{1}(n_{1}-\frac{1}{2}n_{2})^{2}+\frac{1}{4}g_{1}n_{2}(n_{2}+4x_ {e})\]  
In the case that \(n_{2}\) converges, for any \(\delta_{1}>0\), there is a finite time \(t_{\delta_{1}}\), when \(|x_{e}|\geq\delta_{1}\), so that \(\dot{V}<0\). In that case, when \(t\to\infty\), \(x_{e}\to 0\).  
Similarly, it is proved that when \(t\to\infty\), \(y_{e}\to 0\). Since \(|\sin\theta-\sin\theta_{d}|\leq|\theta-\theta_{d}|\), when \(|\sin\theta-\sin\theta_{d}|\) converges and \(t\to\infty,x_{e}\to 0\).  
To sum up, the double closed-loop sliding mode variable structure system designed in this paper is globally and asymptotically stable. The path tracking control law designed in this paper, that is, the input control of vehicle kinematics model is:  
\[\left\{\begin{array}{l}v=u_{1}/\cos\theta_{d}\\ w=\dot{\theta_{d}}-k\big{|}s_{3}\big{|}s_{3}-\varepsilon\big{|}s_{3}\big{|}s \text{sgn}(s_{3})\end{array}\right.\]  
Based on the above control law, the path tracking control model is built in MATLAB/Simulink, as shown in Figure 10. The control parameters of control law are selected as \(p=2.9,g_{1}=10,q=2.9,g_{2}=10,k_{3}=4,\eta_{3}=0.5,a=0.5,b=5\).  
Figure 10: Path Tracking Control Model Based on Sliding Mode Algorithm.
## 2 Polarization State and Observation Analysis
### Wavelength Selection
\begin{table}
\begin{tabular}{c c c} \hline
**Band Center** & **Bandwidth** & **Main Purposes** \\
**(nm)** & **(nm)** & **Absorbent aerosol and ash cloud monitoring** \\
410 & 20 & Aerosol absorption and height, fine mode aerosol size, \\
443 & 20 & aerosol refractive index; cloud masking \\
470 & 20 & Application of joint inversion of liquid water clouds and \\  & & aerosol characteristics on clouds \\
490 & 20 & Aerosols, clouds, sea color, surface albedo \\
532 & 20 & Clouds and aerosols, vegetation \\
555 & 20 & Surface albedo \\ \hline \end{tabular}
\end{table} 
Table 2: Wavelength selection targets of the MEPL.