International audienceAccurate representations of the Earth surface in both spatial and spectral domains are highly desirable in many applications using remotely sensed data. An effective solution is achieved by combining hyperspectral data, which are characterized by a high spectral diversity, with high spatial resolution images, collected by multispectral or panchromatic sensors. In this work, we compare the outcomes provided by fusing single-platform or multi-platform data. We demonstrate that the optimal choice depends on the target spatial resolution to be achieved. To this aim, real images collected by the Hyperion sensor are combined with data acquired by the ALI sensor or the QuickBird sensor assessing the fused outcomes at reduced ...