## 2 Materials and Methods
### Characteristics of the IRIDE Constellation  
One of the most important recent European Earth observation projects is the IRIDE satellite constellation, whose development, which began in 2022, is now entering the new implementation phase, with 47 Italian companies and 20 public entities (like region, in-house enterprises that will be involved in its implementation). The constellation, which will be made up of 69 devices, the first of which will reach orbit in 2025, will exploit multiple observation techniques and will have state-of-the-art satellites at the service of both institutions and national startups and industrial entities. Upon completion, expected by mid-2026, IRIDE will allow a daily revisit of each Italian location, with a ground sampling distance of the order of 2 m. Multispectral and SAR sensors will constitute the payload on-board the satellite. As regards the installation of hyperspectral and thermal sensors, it is not yet totally clear from the information collected which line will be taken as well as the nature of the SAR band. Therefore, the information reported here refers to the beginning of 2024. With certainty, the IRIDE will be the first public higher spatio-temporal resolution space program with all its missions, and the data access will be totally free as stated by ASI. Nevertheless, no information is available at the present time about the registration and access of such data. As previously reported, IRIDE will be made of a set of sub-constellations of LEO satellites (upstream segment) and the ground-based operational infrastructure (downstream segment), as well as services intended for the Italian Public Administration (service segment) first and the rest of Europe second. Concerning the resolution of multispectral, hyperspectral, SARs, and probably thermal sensors, Table 1 reports a general summary. As shown in Table 1, the IRIDE missions involve different sensors and platforms. In particular, the characteristics of those mentioned are given where available and are state of the art. The PLATiNO-1 missions within IRIDE will incorporate a Micro-SAR X payload developed by MetSensing and Thales Alenia Space Italia. The mission involves these two key phases: the first phase operates at 619 km in passive mode, while the second phase operates at 410 km in active mode. It is worth noting that SAR band X will operate between 8 and 12 GHz with wavelengths around 2.4-3.8 cm. Furthermore, the band characteristic enables urban monitoring, as well as ice and snow and canopy tree height detection due to a little penetration into vegetation cover and fast coherence of decay in vegetation areas. The PLATiNO-2 missions within IRIDE outlines the development of the second satellite utilizing the PLATiNO platform, featuring an embedded thermal infrared (TIR) payload. This mission serves to validate the multi-applicability feature of the PLATiNO platform. Developed collaboratively by Leonardo and SITAEL, the PLATiNO-2 TIR payload is designed to capture images that will facilitate essential services for territory control and protection. These services include monitoring bodies of water, glaciers, and pollutants, as well as assessing the state of crops, vegetation, and energy consumption in urban areas. Notably, PLATiNO-2 is equipped with the magnetically shielded HT 100, an enhanced version of the SITAEL electric thruster. This feature positions PLATiNO-2 as one of the pioneering