GNSS Real-Time Tracker & Geospatial Mapper

📌 Project Overview

This project implements a complete pipeline for GNSS data processing. It acquires raw NMEA 0183 sentences from a GPS sensor via a serial port, parses the data to extract positioning information (GGA and RMC sentences), and maps the coordinates onto a georeferenced satellite image of the ENSTA Bretagne campus.

⚙️ How it Works

1. Data Acquisition (acquisition.py)

Connects to a GPS receiver via pySerial (configured for COM7, 4800 baud). It captures the raw bitstream, filters NMEA sentences beginning with $, and logs them into gps_data_nmea.txt.

2. Sentence Parsing (traitement.py)

Utilizes the pynmea2 library to decode:

• GGA Sentences: Extracted for altitude and fix quality.
• RMC Sentences: Extracted for latitude, longitude, and ground speed. The script includes error handling for ParseError to ensure robust processing of noisy serial data.

3. Geospatial Visualization (affichage.py)

• Rasterio Integration: Loads a georeferenced satellite view of the campus.
• Coordinate Transformation: Uses the image's affine transform matrix to convert geographic coordinates (Decimal Degrees) into pixel coordinates (x, y).
• Mapping: Overlays the receiver's real-time or logged position on the map using matplotlib.

🛠 Tech Stack

• Communication: pySerial
• Parsing: pynmea2
• Geospatial Analysis: rasterio, numpy
• Visualization: matplotlib

🚀 Quick Start

1. Hardware: Connect your GPS sensor to your computer.
2. Install Dependencies:

   pip install pyserial pynmea2 rasterio numpy matplotlib

Data Acquisition:

python acquisition.py

Visualization: Ensure ensta_2015.jpg and gps_data_nmea.txt are in the root directory, then:

python affichage.py

📁 Repository Structure

src/acquisition.py: Serial communication and raw data logging.

src/traitement.py: NMEA parsing logic.

src/affichage.py: Image processing and mapping.

data/gps_data_nmea.txt: Sample raw NMEA log file.

docs/Report_GNSS.pdf: Full technical project report.

👥 Authors

Antoine BERTRAND, Samy-William AYYADA, Julien STRUILLOU & Baptiste GUIVARCHE

Academic Context: Developed in 2023 at ENSTA Bretagne.