Comparative analysis on spectral characteristics of PRISMA and EnMAP hyperspectral missions

Given the similarities in their instrumental characteristics, a comparative analysis was conducted between hyperspectral missions of PRISMA, operated by the Italian Space Agency (ASI), and EnMAP, developed by the German Aerospace Center (DLR). This work investigates both the similarities and discrepancies between these two satellite optical data, providing an outline of the spectral regions where data from both sensors can be reliably interchanged. The analysis was performed by analyzing the full visible and near-infrared (VNIR) spectrum and by examining selected spectral ranges sensitive to key environmental parameters, such as nitrogen dioxide, chlorophyll and NDVI. A total of 11 PRISMA and EnMAP co-located hyperspectral image pairs acquired across different seasons over the Euro-Mediterranean region were analyzed, focusing on representative land cover classes (bare soil, vegetation, urban areas and waters). Preprocessing steps were applied to standardize the acquisition viewing geometries, and the top of atmosphere (TOA) level of products from the two sensors were used to avoid inconsistencies introduced by atmospheric correction schemes adopted by each operating agency. Overall, the quantitative and qualitative assessments confirm a strong correspondence between the PRISMA and EnMAP hyperspectral measurements across the VNIR spectrum, with SAM always below 0.1 rad. However, the statistical analysis reveals relatively low consistency between the two sensors for the vegetation sensitive spectral window (750–940 nm), where larger deviations are observed with STD of 0.067 and SAM of 0.097, while the NO 2 spectral range (420–500 nm) shows lower SAM of 0.048 and STD of 0.045.