## 1 Introduction  
Sea surface salinity, as one of the crucial parameters for monitoring climate change on Earth, plays an important role in the global water cycle [1, 2]. MICAP (microwave imager combined active and passive) has been chosen as one of the primary Chinese payloads for ocean salinity observations in the future [3]. In order to meet the detection requirements, considering the high gain characteristics of the parabolic cylindrical antenna, MICAP adopted and designed a parabolic cylindrical reflector antenna [1, 4, 5]. However, the periodic high and low temperatures of the reflector antenna in orbit can cause thermal deformation of the reflector surface, causing it to deviate from the original surface design [6]. These deformations can cause the degradation of antenna electrical performance, influencing detection accuracy [5, 7, 8]. The root mean square (RMS) of the reflector surface's deformation has been used to describe the extent of deformation of the antenna reflector surface and serves as a crucial metric to assess whether this affects the antenna's electrical performance [9]. In engineering, this is a primary way to enhance the stability of antennas and reduce the RMS by designing reinforced ribs for the antennas [10]. In addressing the enhancement of structural stability through the design of reinforced ribs, numerous scholars have conducted extensive research. Research predominantly falls into two categories: 1 Investigating the influence on structural stability by selecting different materials and parameters for the reinforced ribs. [PERSON] et al. [11] conducted simulations by varying the number and height of reinforced ribs for a reflector antenna. The results revealed two conclusions: increasing the number of reinforced ribs significantly enhanced the rigidity of the reflector surface, with a more pronounced effect when increasing the number of circumferential reinforced ribs. Additionally, increasing the height of the reinforced ribs could improve the fundamental frequency of the antenna structure. [PERSON] et al. [12] conducted simulation and experimental research on the thermal deformation of a spaceborne honeycomb sandwich construction rigid reflector. Their study found that, with a constant thickness of the adhesive layer, the thermal deformation of the honeycomb played an important role in the honeycomb sandwich structure. Therefore, the stiffness of the honeycomb should be increased to reduce the thermal deformation of the honeycomb sandwich structure. This finding has reference value for reinforced ribs made with honeycomb sandwich structures. 2 Designing more efficient reinforced ribs using different approaches. [PERSON] et al. [13] divided a reflector antenna into several regions, designed reinforced ribs at the boundaries of each region, and then designed reinforced ribs in both circumferential and radial directions, based on the characteristics of the reflector surface. Finally, auxiliary reinforced ribs were placed on the contours of the reflector surface, forming the final layout. The design ultimately improved the overall structural stability, while reducing weight. In contrast to traditional designs that are reliant on designer expertise, topology optimization, by setting response types, response constraints, and optimization objectives, facilitates the calculation of material layouts and appropriate dimensions. This has been widely studied in fields such as structural design [14; 15; 16]. [PERSON] et al. [17] adopted the minimization of overall structural flexibility as the optimization objective, with the total mass of the primary mirror as the response constraint. Size optimization of the height of reinforced ribs was then performed, ultimately demonstrating the significant effectiveness of the reinforced rib structure in reducing optical surface deviations caused by self-weight and polishing pressure loads. In addressing the primary mirror assembly of large-aperture space telescopes, [PERSON] et al.