🚗 Doppler Speed Predictor 🎯

Introduction

This program demonstrates how to predict car speed from audio file using the Doppler Effect and a MATLAB simulation. Frequency analysis is performed on the audio file to determine the detected frequency when the car is approaching and when the car has passed. This information can then be fed into the Doppler equation to determine the speed of the car during the pass by using the ratio of the incoming and outgoing frequencies.

---

📡 How It Works

When a sound source moves relative to an observer, the frequency perceived is shifted. This project uses that principle to reverse-calculate velocity.

Doppler Shift Equation:

[ f' = f \left( \frac{v + v_o}{v - v_s} \right) ] Where:

• ( f ) = emitted frequency
• ( f' ) = observed frequency
• ( v ) = speed of sound
• ( v_o ), ( v_s ) = velocity of observer/source

The script simulates these parameters and solves for the unknown velocity.

---

Audio Samples

Original Audio

Peak Frequency -> Oncoming

Peak frequency approximately 365Hz.

Peak Frequency -> Outgoing

Peak frequency approximately 328Hz.

Doppler Equation

• Vs = 343 m/s
• fin = 365 Hz
• fout = 328 Hz

Frequency Ratio

---

🛠️ Tools & Technologies

• 🧮 MATLAB
• 📊 Signal Processing Toolbox
• 📁 .m script files

---

🚀 Getting Started

1. Clone the repo:

   git clone https://github.com/Yasteer/Doppler-Speed-Predictor.git

2. Open the main .m file in MATLAB
3. Run the simulation and observe the predicted speed and plots

---

💡 Future Ideas

Real-time input from audio files

Integration with a microphone for real-world testing

GUI for user interaction

---

📬 Contact

Built with ❤️ by Yasteer