ONERA

SARLO-80: Large-scale VHR SAR-optical-text dataset for multimodal foundation model training

Researchers from ONERA release SARLO-80, a dataset of 119,566 triplets combining very-high-resolution complex SAR imagery, aligned optical patches, and natural-language captions covering 257 locations across 72 countries. The dataset is built from Umbra spotlight acquisitions standardized to an 80cm slant-range grid, with three caption variants per sample to support vision-language training and evaluation. It addresses a recognized gap in SAR-optical multimodal resources, which have historically been limited to low-resolution intensity-only products. The dataset and preprocessing code are publicly released on Hugging Face Hub.