pygndc

Geographic Neural Data Cube — a Python SDK for reading and analyzing .gndc compressed geospatial time-series data.

What is GeoNDC?

GeoNDC is a continuous-time, AI-ready representation of Earth observation archives. Unlike traditional Analysis-Ready Data (cloud-corrected raster files) or geospatial foundation model embeddings (abstract feature vectors), GeoNDC preserves the original physical observables — surface reflectance, vegetation indices, biophysical variables — while enabling millisecond-level random-access queries at any (x, y, t) coordinate.

Each archive (MODIS, Sentinel-2, Landsat, HiGLASS, …) is encoded into a single self-contained .gndc file (typically 0.5–2 GB) that runs on a laptop, a server, or directly in a browser via WebGPU. Data providers train the model once and publish the file; users download it and run inference locally — the compressed form is the analysis-ready form. No hosted runtime, no API quota, no vendor lock-in.

Key Capabilities

• Continuous-time reconstruction — query data at any moment, not just original observation times
• Millisecond random access — point time series in ~7 ms, full-frame reconstruction in ~2 s on a consumer GPU
• Analytic gradients — compute spatial/temporal derivatives directly from the neural network
• Compact storage — typically ~100:1 versus Int16 raster baselines, up to ~400:1 versus raw float archives
• Portable Native encoder and decoder — the default CPU/WGPU path needs no PyTorch, Numba, CUDA toolkit, or runtime JIT; WGPU targets Vulkan, DX12, and Metal, while Torch and tiny-cuda-nn remain optional compatibility extras
• Implicit gap-filling — cloud-occluded surfaces are reconstructed from the learned spatiotemporal field
• Multi-sensor support — Sentinel-2, Landsat, MODIS, HiGLASS, and more

Online Viewer & Sample Data

• Web Viewer: Browse .gndc files directly in the browser via WebGPU at geondc.org/viewer — no installation required, GPU-accelerated, runs entirely client-side.
• Sample Data: Download .gndc datasets from Hugging Face.

Documentation

• TUTORIAL.md — Installation, quick-start, CLI commands, end-to-end usage examples.
• API_Reference.md — Full Python API for pygndc.open(), GNDCDataset, GNDCReader, analysis functions.

Installation Extras

The default wheel includes the native CPU/WGPU runtime, encoder, GeoTIFF I/O, and core Python API. The desktop viewer is optional:

pip install pygndc[viewer]

License

GeoNDC is proprietary binary software. Decoder operations may be used without an encoder license; creating or exporting .gndc data requires a valid encoder license. See LICENSE for the complete terms.

The GeoNDC file-format specification is published separately to support interoperability. Previously released copies remain governed by the license that accompanied those copies.

Citation

@misc{qi2026geondcqueryableneuraldata,
  title={GeoNDC: A Queryable Neural Data Cube for Planetary-Scale Earth Observation},
  author={Jianbo Qi and Mengyao Li and Baogui Jiang and Yidan Chen and Qiao Wang},
  year={2026},
  eprint={2603.25037},
  archivePrefix={arXiv},
  primaryClass={cs.CV},
  url={https://arxiv.org/abs/2603.25037},
}

Contact

• Author: Jianbo Qi
• Email: jianboqi@126.com
• Issues: GitHub Issues