---
license: apache-2.0
base_model: facebook/VGGT-1B
tags:
  - georay
  - satellite-imagery
  - satellite-photogrammetry
  - remote-sensing
  - 3d-reconstruction
  - multi-view-stereo
  - rational-polynomial-camera
  - digital-surface-model
  - pytorch
  - research
arxiv: 2608.29680
---

# GeoRay

**Gauge-Aware Feed-Forward Satellite 3D Reconstruction in the Geodetic Frame**

[Paper](https://arxiv.org/abs/2608.29680) · [Code](https://github.com/HIT-SIRS/GeoRay) · [Issues](https://github.com/HIT-SIRS/GeoRay/issues)

GeoRay is a feed-forward framework for reconstructing dense satellite surface height directly in the absolute geodetic frame under rational polynomial cameras (RPCs). It combines RPC height-ray reasoning, gauge-aware relief–datum separation, and uncertainty-calibrated monocular/multi-view fusion.

## Model details

- **Architecture:** frozen VGGT-1B and MoGe-2 backbones with lightweight GeoRay adaptation, relief, datum, calibration, and uncertainty modules
- **Inputs:** three-view satellite image patches and forward RPC coefficients
- **Outputs:** absolute surface height and predictive uncertainty; optional longitude/latitude/height back-projection
- **Framework:** PyTorch 2.7.x
- **Code license:** Apache-2.0
- **Checkpoint file:** `georay_ckpt.pt`
- **Checkpoint SHA-256:** `7bbe1fc5f04d471d1ecd843be94b73571d8e6aded9a407965277cf37a1a3f330`

The released checkpoint contains GeoRay's trainable modules. Frozen backbone weights are obtained separately and remain subject to their upstream licenses.

## Results

On 26 held-out US3D tiles, GeoRay reports:

| Metric | Result |
|:--|--:|
| Absolute MAE ↓ | **2.99 m** |
| Coverage ↑ | **91.9%** |
| Completeness-aware accuracy gain ↑ | **+46.4 points** over the strongest compliant feed-forward baseline |
| Model-forward time ↓ | **24.0 s / tile** in the reported setting |

See the [paper](https://arxiv.org/abs/2608.29680) for the complete evaluation protocol, cross-dataset and cross-city results, and baseline definitions.

## Installation

```bash
git clone https://github.com/HIT-SIRS/GeoRay.git
cd GeoRay
conda create -n georay python=3.11 -y
conda activate georay

# Install the CUDA-enabled PyTorch 2.7.x build appropriate for your system first.
pip install -r requirements.txt
pip install -e .
```

Follow the repository [installation guide](https://github.com/HIT-SIRS/GeoRay#installation) to prepare the pinned VGGT code and external frozen weights.

## Download

After this model repository is published, download the checkpoint with:

```bash
hf download hit-sirs/GeoRay georay_ckpt.pt --local-dir checkpoints/GeoRay
export GEORAY_CKPT="$PWD/checkpoints/GeoRay/georay_ckpt.pt"
```

## Inference

```bash
python scripts/infer.py \
  --ckpt "$GEORAY_CKPT" \
  --config configs/train.yaml \
  --input /path/to/tile.tar \
  --out_dir outputs/tile

python scripts/export_dsm.py \
  --infer_out outputs/tile \
  --out_dir outputs/tile \
  --input /path/to/tile.tar
```

The input WebDataset format and RPC requirements are documented in the [GeoRay README](https://github.com/HIT-SIRS/GeoRay#data-format).

## Intended use

GeoRay is intended for research on satellite multi-view 3D reconstruction, absolute-frame surface-height estimation, uncertainty-aware photogrammetry, and related geospatial studies.

## Limitations

- The released model expects the preprocessing and three-view WebDataset structure documented by the project.
- Accuracy is not guaranteed for unseen sensors, geographic regions, RPC conventions, or height datums; validate outputs before downstream use.
- The exported product is a predicted digital surface model, not a surveyed digital terrain model.
- Predictive uncertainty is a model estimate and must not be treated as a formal safety guarantee.
- Inference requires an NVIDIA GPU and separately obtained frozen backbone weights.

## Third-party components

GeoRay source code and its lightweight checkpoint are released under Apache-2.0. VGGT-1B, MoGe-2, and other third-party components are governed by their own licenses. In particular, users must review the applicable VGGT weight license before use or redistribution.

## Citation

```bibtex
@article{dong2026georay,
  title   = {GeoRay: Gauge-Aware Feed-Forward Satellite 3D Reconstruction in the Geodetic Frame},
  author  = {Dong, Zhe and Wu, Wanqing and Sun, Yuzhe and Jiang, Haochen and Ma, Yuchen and Ren, Lecheng and Liu, Tianzhu and Gu, Yanfeng},
  journal = {arXiv preprint arXiv:2608.29680},
  year    = {2026}
}
```