Inter-Sensor Remote Sensing Image Enhancement For Operational Sentinel-2 And Sentinel-3 Data Products

The recent availability of operational data from the Sentinel-2 and Sentinel-3 missions provides widespread opportunities to generate diverse high-level remote sensing products. However, the synergies between both multi-spectral instruments are often difficult to exploit from an operational perspective. Standard pansharpening algorithms may encounter important disadvantages due to the limited inter-sensor data availability in actual production environments. Moreover, the lack of a real high-resolution ground-truth for super-resolution techniques may affect the radiometric quality of the final result. In this scenario, this work investigates the viability of using the Multi-Spectral Instrument of Sentinel-2 for super-resolving data products acquired by the Ocean and Land Colour Instrument of Sentinel-3. Specifically, we define an inter-sensor image enhancement framework which combines a PCA-based component substitution pansharpening scheme with a CNN-based spatial enhancing super-resolution mapping. The conducted experiments reveal the suitability of the proposed approach for generating Level-4 data products within the Copernicus programme context.