C2NET-ExtremaduraData: A paired satellite–in-situ chlorophyll-a dataset for 32 reservoirs in Extremadura, Spain (2017–2022)

v1.0.0 — Initial public release First public release of C2NET-ExtremaduraData, a paired satellite–in-situ chlorophyll-a (Chl-a) dataset for 32 small inland reservoirs in Extremadura (southwestern Spain), covering the period 2017–2022. In-situ Chl-a was measured by the Junta de Extremadura. For each in-situ measurement, Chl-a was retrieved from Sentinel-2 MSI Level-1C imagery atmospherically corrected with three C2-Net processors (C2RCC, C2X, C2XC) in ESA SNAP, using a 7×7-pixel maximum-value estimator. Of 138 in-situ measurements, the 94 coinciding with a cloud-free acquisition form the complete satellite–in-situ pairs. Contents samples.csv — 94 paired records (Reservoir, Date, In_situ, C2RCC, C2X, C2XC) metadata.csv — 32 reservoirs with coordinates, basin, morphometry, in-situ Chl-a statistics and trophic state figures/reservoirs.png — study-area map README.md — full documentation and variable dictionary Notes UTF-8 encoding; dates in ISO 8601 (YYYY-MM-DD); decimal separator is a point. Chl-a statistics in metadata.csv are computed over all 138 in-situ measurements; samples.csv contains the 94 satellite-paired records. Associated publications Data descriptor: submitted to Data in Brief. Related research article: Torrecilla-Pinero et al. (2026), Int. J. Appl. Earth Obs. Geoinf. 152, 105415. https://doi.org/10.1016/j.jag.2026.105415 License Data: CC BY 4.0