GNSS-IR Real-Time Water Level Processing

A Python-based command line tool for real-time processing of low-cost GNSS-IR (Global Navigation Satellite System Interferometric Reflectometry) water level data.

About

This software accompanies the research article "Real-time water levels using GNSS-IR: a potential tool for flood monitoring" by Purnell et al., published in Geophysical Research Letters (2024).

Installation

From PyPI (recommended)

pip install gnssir-rt

From Source

For an editable install:

git clone https://github.com/purnelldj/gnssir-rt.git
cd gnssir-rt
pip install -e .

Quick Start

Here's a complete example using test data from Saint-Joseph-de-la-Rive:

Step 1: Download Test Data

# Download the test dataset
wget https://github.com/purnelldj/gnssir-rt/raw/main/tests/data/sjdlr.zip

# Create data directory and extract to it
mkdir -p gnssir-data
unzip sjdlr.zip -d gnssir-data

Step 2: Process the Data

gnssir --task arcs2splines --site_dir gnssir-data/sjdlr --config gnssir-data/sjdlr/sjdlr.yaml

This will generate a plot showing one day of processed water level data, as shown below.

Usage

General Command Structure

gnssir --task TASK --site_dir SITE_DIR --config path/to/config.yaml

Configuration Options

You can either change parameters directly in a configuration file or from the command line as shown below.

gnssir --task arcs2splines --site_dir gnssir-data/sjdlr --config gnssir-data/sjdlr/sjdlr.yaml \
       --azilims '[190, 230]'

Help and Documentation

gnssir --help  # Show all available parameters

Data

Research Dataset

The complete SNR dataset used in the accompanying research paper is available on Zenodo: 10.5281/zenodo.10114719

To download the dataset:

pip install zenodo_get
zenodo_get 10.5281/zenodo.10114719

Note: The download is approximately 1GB.

SNR Data Format

The software expects SNR data in a specific format similar to the gnssrefl format, with the following modifications:

Column	Description
1	Satellite number
2	Elevation angle (degrees)
3	Azimuth angle (degrees)
4	GPS time (instead of seconds of day)
5	L1 SNR values

Contributing

We welcome contributions from the community! Whether you're fixing bugs, adding features, improving documentation, or sharing new site configurations, your help is appreciated.

How to Contribute

1. Fork the repository on GitHub
2. Clone your fork locally:

   git clone https://github.com/yourusername/gnssir-rt.git
   cd gnssir-rt

3. Create a new branch for your feature:

   git checkout -b feature/your-feature-name

4. Make your changes and test them thoroughly
5. Commit your changes with clear, descriptive messages:

   git commit -m "Add feature: description of your changes"

6. Push to your fork and submit a pull request

Development Setup

For development work:

pip install -e ".[dev]"  # Install with development dependencies
python -m pytest         # Run tests

License

This project is licensed under the BSD 3-Clause License - see the LICENSE file for details.

Citation

If you use this software in your research, please cite:

Purnell, D., et al. (2024). Real-time water levels using GNSS-IR: a potential tool
for flood monitoring. Geophysical Research Letters.
https://doi.org/10.1029/2023GL105039

Acknowledgments

• The script make_gpt.py was adapted from the gnssrefl repository
• This work builds upon the broader GNSS-IR research community's contributions

Support

• Issues: Report bugs or request features via GitHub Issues
• Discussions: Join community discussions in GitHub Discussions
• Email: For direct inquiries, contact the maintainers

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Keywords: GNSS-IR, water level monitoring, flood detection, interferometric reflectometry, remote sensing