GeoVeil-MP: GNSS Multipath Analysis Library

A high-performance Rust library for GNSS multipath analysis with Python bindings. Part of the GeoVeil suite for GNSS signal quality analysis.

Features

• 🛰️ RINEX Support: Full support for RINEX v2.xx, v3.xx, and v4.xx observation files
• 🌍 Multi-GNSS: GPS, GLONASS, Galileo, BeiDou, QZSS, NavIC/IRNSS, SBAS
• 📡 Navigation Data:
  • Broadcast ephemerides (Keplerian elements)
  • GLONASS state vector propagation (4th-order Runge-Kutta)
  • SP3 precise orbit interpolation (Neville's algorithm)
• 📊 Multipath Analysis: Code multipath estimation using linear combinations
• ⚡ Cycle Slip Detection: Ionospheric residuals and code-phase combinations
• 📍 Position Estimation: Least squares SPP with DOP calculation
• 🎨 Visualization: R plotting integration for publication-quality figures
• 🚀 High Performance: Parallel processing with Rayon, memory-mapped I/O
• 🐍 Python Bindings: Full Python API via PyO3

Installation

Python (PyPI)

pip install geoveil-mp

Rust (Cargo)

[dependencies]
geoveil_mp = "0.1"

Or with all features:

[dependencies]
geoveil_mp = { version = "0.1", features = ["full"] }

From Source

# Clone the repository
git clone https://github.com/miluta7/geoveil-mp.git
cd geoveil-mp

# Build Rust library
cargo build --release

# Build Python wheel
pip install maturin
maturin develop --release --features python

Quick Start

Python Usage

import geoveil_mp as gm

# Read RINEX observation file
obs = gm.read_rinex_obs("observation.24o")
print(f"Loaded {obs.num_epochs} epochs, {obs.num_satellites} satellites")

# Read SP3 precise ephemeris (optional, for accurate elevations)
sp3 = gm.read_sp3("ephemeris.sp3")

# Create analyzer with elevation cutoff
analyzer = gm.MultipathAnalyzer(
    obs,
    elevation_cutoff=10.0,
    systems=["G", "E", "R", "C"]  # GPS, Galileo, GLONASS, BeiDou
)

# Run multipath analysis
results = analyzer.analyze()

# Compute satellite elevations from SP3
if sp3 and obs.approx_position:
    computed, failed = results.compute_elevations(sp3, obs.approx_position)
    print(f"Elevations: {computed} computed, {failed} failed")

# Access results
print(f"Total estimates: {results.total_estimates()}")
print(f"Cycle slips detected: {results.total_cycle_slips()}")

# Print statistics by signal
for stat in results.statistics:
    print(f"{stat.signal}: RMS={stat.rms:.4f}m, Count={stat.count}")

# Export to CSV
import pandas as pd
data = [{
    'satellite': e.satellite,
    'epoch': e.epoch,
    'mp_value': e.mp_value,
    'elevation': e.elevation,
    'signal': e.signal
} for e in results.estimates]
df = pd.DataFrame(data)
df.to_csv("multipath_results.csv", index=False)

Rust Usage

use geoveil_mp::{
    prelude::*,
    RinexObsReader, Sp3Reader,
    navigation::SatellitePositionProvider,
};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Read RINEX observation file
    let obs_data = RinexObsReader::new().read("observation.24o")?;
    
    // Read SP3 precise ephemeris
    let sp3_data = Sp3Reader::read("ephemeris.sp3")?;
    
    // Configure analysis
    let config = AnalysisConfig::default()
        .with_elevation_cutoff(10.0)
        .with_systems(&["G", "E", "R", "C"]);
    
    // Run multipath analysis
    let analyzer = MultipathAnalyzer::new(obs_data, config);
    let results = analyzer.analyze()?;
    
    // Export results
    results.to_csv("results.csv")?;
    
    // Print statistics
    for (signal, stats) in &results.statistics {
        println!("{}: RMS={:.4}m, Count={}", signal, stats.rms, stats.count);
    }
    
    Ok(())
}

CLI Usage

# Analyze RINEX file with SP3 orbits
geoveil-mp analyze --obs observation.24o --sp3 ephemeris.sp3 --csv results.csv

# Get file information
geoveil-mp info observation.24o

# Estimate position from pseudoranges
geoveil-mp position --obs observation.24o --nav navigation.24n

Multipath Estimation

The code multipath is estimated using the linear combination:

$$MP_1 = R_1 - \left(1+\frac{2}{\alpha - 1}\right)\Phi_1 + \left(\frac{2}{\alpha - 1}\right)\Phi_2$$

where:

• $R_1$ is the code observation on frequency 1
• $\Phi_1, \Phi_2$ are phase observations on frequencies 1 and 2
• $\alpha = f_1^2/f_22$ is the frequency ratio squared

This combination eliminates ionospheric delay and geometry, leaving only code multipath, code noise, and ambiguity-related biases.

Supported GNSS Systems

Data Sources

SP3 Precise Orbits (No Authentication Required)

ESA:  http://navigation-office.esa.int/products/gnss-products/{week}/
GFZ:  https://igs.bkg.bund.de/root_ftp/IGS/products/mgex/{week}/
CODE: https://igs.bkg.bund.de/root_ftp/IGS/products/mgex/{week}/

Broadcast Navigation

BKG:  https://igs.bkg.bund.de/root_ftp/IGS/BRDC/{year}/{doy}/
IGN:  https://igs.ign.fr/pub/igs/data/{year}/{doy}/

Python API Reference

Classes

Functions

Constants

Architecture

geoveil_mp/
├── src/
│   ├── lib.rs              # Library entry point
│   ├── python.rs           # Python bindings (PyO3)
│   ├── rinex/              # RINEX parsing
│   │   ├── types.rs        # Data structures
│   │   └── obs_reader.rs   # Observation file reader
│   ├── navigation/         # Ephemeris handling
│   │   ├── types.rs        # Ephemeris types
│   │   ├── kepler2ecef.rs  # Keplerian to ECEF
│   │   ├── glonass.rs      # GLONASS Runge-Kutta
│   │   └── sp3.rs          # SP3 Neville interpolation
│   ├── analysis/           # Analysis algorithms
│   │   ├── multipath.rs    # Multipath estimation
│   │   ├── cycle_slip.rs   # Cycle slip detection
│   │   └── position.rs     # Position estimation
│   ├── plotting/           # R integration
│   └── utils/              # Utilities
│       ├── constants.rs    # Physical constants
│       ├── coordinates.rs  # Coordinate transforms
│       ├── time.rs         # Time handling
│       └── error.rs        # Error types
├── examples/
├── tests/
└── r_scripts/              # R plotting scripts

Performance

Benchmarks on a typical 24-hour multi-GNSS RINEX file (~100MB):

Related Projects

• geoveil-cn0: CN0 (carrier-to-noise ratio) analysis and interference detection
• GNSS_Multipath_Analysis_Software: Original Python implementation (inspiration)

References

• RINEX 4.02 Specification (IGS/RTCM)
• GPS Interface Control Document (IS-GPS-200)
• GLONASS Interface Control Document (ICD-GLONASS)
• Galileo OS-SDD (Open Service Signal-in-Space ICD)
• IGS Multi-GNSS Experiment (MGEX)

License

MIT License - see LICENSE file for details.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

Changelog

See CHANGELOG.md for version history.