HF-NeRF: UAV remote sensing image reconstruction via height-augmented representation and frequency-adaptive sampling

Existing neural radiance field (NeRF) 3D reconstruction methods have demonstrated significant potential in scene modeling. However, although NeRF shows good performance in 3D reconstruction, it still faces practical challenges when processing remote sensing images captured by Unmanned Aerial Vehicle, such as differences in geometric properties between the height and horizontal dimensions and insufficient efficiency in ray sampling. To address this, this paper proposes a novel UAV remote sensing scene reconstruction framework, HF-NeRF, which incorporates a Height-Enhanced Representation (HER) module. This module performs independent encoding and MLP mapping for the height dimension z, thereby capturing geometric features across different height layers. In parallel, a Frequency-Adaptive Sampling (FAS) approach, which analyzes energy distribution in the frequency domain, adaptively modulates sampling density to improve computational performance and preserve fine-grained details. Experimental results on both a proprietary UAV remote sensing dataset and publicly available datasets demonstrate that the proposed reconstruction approach excels over leading NeRF derivatives in overall performance for remote sensing imagery.