Mind the Gap: Quantifying the Domain Gap in Cross-Sensor Diffusion Super-Resolution
This study addresses the domain gap between synthetic training data and real-world remote sensing imagery in cross-sensor super-resolution. It presents the first systematic evaluation of diffusion models on real Sentinel-2 and PlanetScope images, uncovering critical challenges in synthetic-to-real domain transfer. Leveraging a large-scale geometrically and temporally aligned dataset, the work integrates five state-of-the-art diffusion architectures with self-supervised learning and introduces LPIPS-Sat, a novel perceptual metric tailored for quantifying the domain discrepancy in satellite imagery. The findings reveal that models trained on synthetic data suffer significant performance degradation when applied to real scenes, while those trained directly on real data encounter optimization difficulties and struggle to generalize across the physical and radiometric diversity inherent in actual satellite observations, thereby highlighting fundamental limitations of current approaches.