SAT-NGP : Unleashing Neural Graphics Primitives for Fast Relightable Transient-Free 3D reconstruction from Satellite Imagery
Camille Billouard, Dawa Derksen, Emmanuelle Sarrazin, Bruno Vallet
TL;DR
SAT-NGP tackles the challenge of building accurate 3D reconstructions from multi-date satellite imagery where illumination, shadows, and transient objects cause inconsistencies. It combines a multi-resolution hash encoding inspired by Instant Neural Graphics Primitives with a lightweight NeRF architecture, solar-angle conditioning via SH, a robust loss for transient suppression, and UTMs-based scene representation to achieve relightable, transient-free DSMs. The approach delivers dramatic speedups (training in about $15$ minutes) while maintaining DSM quality comparable to slower NeRF variants, and it removes transient objects from the novel-view synthesis. The work enables scalable, high-quality 3D reconstruction over large satellite datasets on modest GPU resources, with code to be released.
Abstract
Current stereo-vision pipelines produce high accuracy 3D reconstruction when using multiple pairs or triplets of satellite images. However, these pipelines are sensitive to the changes between images that can occur as a result of multi-date acquisitions. Such variations are mainly due to variable shadows, reflexions and transient objects (cars, vegetation). To take such changes into account, Neural Radiance Fields (NeRF) have recently been applied to multi-date satellite imagery. However, Neural methods are very compute-intensive, taking dozens of hours to learn, compared with minutes for standard stereo-vision pipelines. Following the ideas of Instant Neural Graphics Primitives we propose to use an efficient sampling strategy and multi-resolution hash encoding to accelerate the learning. Our model, Satellite Neural Graphics Primitives (SAT-NGP) decreases the learning time to 15 minutes while maintaining the quality of the 3D reconstruction.
