## 2 Materials and Methods  
### Study Area  
The study area, shown in Figure 1, is an urban area located in the western part of the city of Naples, the regional capital of Campania in southern Italy. This study area presents an interesting opportunity to test out pansharpening in an urban area. Naples shares many struggles in managing urban trees common throughout southern Europe. The metropolitan city of Naples has a population of just under 3,000,000 individuals (Istat 2023), and is spread over 1171 km\({}^{2}\) with an extremely high population density of 2519 residents per km\({}^{2}\)[43]. In the European Commission's 2023 _Quality of Life in European Cities Perception Survey_, only 66% of participating residents reported being satisfied with their city, placing Naples 5 th from the bottom in an investigation of 83 cities across the European Union (EU), European Free Trade Association (EFTA), the United Kingdom, the western Balkans, and Turkiye (European Commission, 2023). Aside from poor satisfaction with employment, safety, government, healthcare, public transport, and cultural facilities, Naples also stood out as ranking 8 th from last for noise (only 38% of participants were satisfied with the noise level), 5 th from last for satisfaction with cleanliness (25% satisfied), 6 th from last for being a good place for older people to live (only 55% of participants agreed), 4 th from last for being a good place for families with young children (only 58% agreed), and 2 nd from last for satisfaction with public spaces (45% satisfied). All of these components contributing to quality of life are strongly related to the presence of urban green spaces, which provides opportunities for cohesion, abates noise, and improves city decor, among other benefits. That is why the Sustainable Development Goal (SDG) target 11.7 specifically aims to \"provide universal access to safe, inclusive, and accessible green and public spaces, in particular for women and children, older persons, and persons with disabilities\" [17]. Most relevantly, Naples scored absolutely last for satisfaction with green spaces in the city (only 31% of residents were satisfied), with the report identifying a strong correlation between accessibility and spatial distribution. Specifically, as of the city's last Tree Audit in 2021, the municipality of Naples included 5,554,236 m\({}^{2}\) of green spaces, which were challenging to maintain due to diminishing staff, which fell by 77% between 2016 and 2021 [44]. Although the city was responsible  
Figure 1: Study area—Region of interest (ROI). for 50 public parks, only 36 of these were open to the public. However, at the time of the audit, the municipality was active in approving the financing and construction of several renovations and new parks, as well as for other urban greening measures. In terms of tree cover, the municipality estimated having about 40,000 trees, based on a partial inventory of 28,213 specimens. A total of 9% of these were found to be at high or extreme risk of collapsing. In fact, between 2016 and 2021, 2791 trees had to be removed, mainly due to collapses or damage caused by extreme weather events. During the same time span, only 707 new trees were planted. However, at the time of the report, the city had just approved a plan to plant 5600 trees, replacing collapsed or unstable specimens, and adding new trees to city streets and public parks [44]. The specific region of interest (ROI) that is analyzed in this study is a 2 \(\times\) 3 km rectangle, with an additional 200 m buffer applied to avoid edge effects and potential errors in subsequent processing. Various reasons have led to the selection of this specific ROI as an emblematic case for an investigation into urban tree distribution.