Lueven, February 2024
In late summer 2024, an aerial survey was conducted over the city of Leuven (size of about 57 km²) to collect data using multiple airborne sensors simultaneously. This initiative, as part of ongoing climate adaptation projects, aims to acquire data for geospatial and environmental analysis, helping identify areas in the city where nature-based solutions can be implemented.
The flight was executed in clear sky conditions using a Cessna 404 aircraft, equipped with the AisaFENIX 384 sensor by SPECIM and the Dual-DigiTHERM camera by IGI, following 19 strips in North-South direction, in order to guarantee high quality of the hyperspectral data. The flight duration was approximately 90 minutes. The hyperspectral images have a spatial resolution of 2 m on the ground and cover the VNIR (400–970 nm) and SWIR (970–2500 nm) spectral ranges with 360 narrow bands. Simultaneously the thermal images have a ground spatial resolution of 50 cm and cover the LWIR spectral range (7.5–14 μm)..
The airborne data serves as a crucial resource for supporting the municipality of Leuven in tackling its climate challenges. High-resolution hyperspectral images reveal detailed information about the materials that make up the city’s urban landscape — from the densely built city centre to the suburban areas and the sparsely populated farmland on its outskirts. Beyond identifying surface materials, these images also enable the derivation of various ecological indexes, providing valuable insights for research purposes.
With urban heat islands and thermal comfort being pressing concerns for both the city administration and its residents, thermal maps offer critical insights, complementing the weather data gathered by the local citizen science network, Leuven.cool.
A more detailed understanding of Leuven's temperature distribution will support the city administration in planning and prioritizing projects across different neighbourhoods. Within USAGE, an analysis of ground materials in these areas quantified the ratio of hardened to green surfaces and identified potential zones for unsealing. Incorporating an additional layer of emissivity data will further guide the prioritization of unhardening initiatives.
