## 4 SAR System Requirements Effect on Satellite Design
### SAR System Optimization by Using ModeFRONTIER  
ModeFRONTIER is a multidisciplinary and multi-objective optimization software platform that integrates various tools for optimizing designs. It is used across industries to enhance product performance, reduce costs, and improve efficiency. The platform enables users to create sophisticated workflows that automate the design process, allowing for the comprehensive exploration and optimization of design variables [71; 72; 73]. In the context of a SAR system, modeFRONTIER can be utilized to optimize system parameters to achieve the desired performance metrics. SAR systems, which are used for high-resolution imaging, require careful tuning of parameters to balance resolution, coverage area, and signal-to-noise ratio (SNR). Using modeFRONTIER 2020R3 for optimizing SAR system parameters can significantly enhance system performance by systematically exploring the design space and identifying optimal configurations. By following the outlined steps, we can efficiently set up and execute the optimization process, leading to a well-balanced and \begin{table}
\begin{tabular}{l l l l l l l l l l l} \hline \hline
**Altitude** & **Incidence** & **System** & **Duty** & **Band** & **Pulse** & **Azimuth-** & **Antenna** & **NESZ** & **Swath** & **PRF** \\  & **Angle** & **Losses** & **Cycle** & **Width** & **Width** & **Resolution** & **Antenna** & **Dimensions** & **NESZ** & **Swath** & **PRF** \\ \hline \hline
**Scenario-1** & & & & & & & & & & & & \\
500 km. & 30\({}^{\circ}\) & 5 dB & 0.25 & 150 MHz & 5 & 3 m \(\times\) 3 m & 3 m \(\times\) 10 m & \(-\)4 dB & 1800 km & 2500 Hz \\ \hline
**Scenario-2** & & & & & & & & & & & \\
600 km. & 30\({}^{\circ}\) & 5 dB & 0.25 & 100 MHz & 5 & 5 m \(\times\) 5 m & 2 m \(\times\) 8 m & 2 dB & 2800 km & 2700 Hz \\ \hline
**Scenario-3** & & & & & & & & & & \\
700 km. & 30\({}^{\circ}\) & 1 dB & 0.25 & 200 MHz & 1 & 5 m \(\times\) 5 m & 2 m \(\times\) 10 m & 8 dB & 2500 km & 2500 Hz \\ \hline
**Scenario-4** & & & & & & & & & & \\
600 km & 30\({}^{\circ}\) & 12 dB & 0.1 & 200 MHz & 1 & 10 m \(\times\) 10 m & 2 m \(\times\) 10 m & 13 dB & 2100 km & 1000 Hz \\ \hline
**Scenario-5** & & & & & & & & & & \\
600 km. & 30\({}^{\circ}\) & 3 dB & 0.25 & 100 MHz & 5 & 1 m \(\times\) 1 m & 3 m \(\times\) 10 m & \(-\)7 dB & 2150 km & 2200 Hz \\ \hline \hline \end{tabular}
\end{table} 
Table 3: System design scenarios. high-performing SAR system. An algorithm is employed through modeFRONTIER 2020R3 to optimize the transmitting power and antenna area requirements of a SAR satellite while achieving the best system performance in terms of NESZ (noise-equivalent sigma zero). Figure 10 shows the modeFRONTIER optimization flow. The objective is to minimize transmitting power and antenna area while minimizing the NESZ value to obtain a better system performance. The constraints are the system performance requirements, physical limitations of the satellite, and operational constraints. When the workflow is set up, the first step is to import models which means integrating SAR system models (including the power consumption of the payload, antenna area, and NESZ calculation models) into modeFRONTIER. When building the workflow, input parameters for design variables (transmitting power, antenna area, etc. ), simulation nodes to evaluate NESZ based on input parameters, and outputs for measuring performance need to be defined. The transmitting power, antenna area and other relevant parameters are other design variables. Choosing an optimization algorithm means selecting a suitable optimization algorithm (e.g., genetic algorithm, NSGA-II) that handles multi-objective optimization. NSGA-II is used in our study. When the workflow is run, modeFRONTIER will vary the design variables within the specified ranges. Each combination of variables will be evaluated for the NESZ, the transmitting power of the payload, and the antenna area.