Dead reckoning (DR) in inertial navigation refers to the process of determining a vehicle’s current position based on its previously known position, velocity, and heading over time—without external references like GPS. An Inertial Navigation System (INS) relies on accelerometers and gyroscopes to continuously compute position changes, making dead reckoning a fundamental principle of inertial navigation.
How Dead Reckoning Works in INS
Initial Position – Starts from a known GPS position or manually input coordinates.
Velocity & Heading Calculation – INS sensors track acceleration and angular rotation.
Position Update – Uses integration of acceleration and velocity over time to estimate new location.
Advantages of Dead Reckoning in INS
✔ Works Without GPS – Effective in GPS-denied environments (e.g., underground, underwater, military operations).
✔ Real-Time Navigation – Provides continuous tracking without needing satellites.
✔ Highly Reliable for Short Durations – Offers precise movement tracking over short distances.
Challenges of Dead Reckoning in INS
✔ Drift Over Time – Small sensor errors accumulate, leading to position drift without external corrections.
✔ Needs Periodic Updates – Best when combined with GNSS, odometers, or external sensors to correct long-term errors.
How INS Reduces Dead Reckoning Errors
• Kalman Filtering – Fuses data from IMU, GNSS, and external sensors to minimize drift.
• Multi-Sensor Integration – Uses wheel speed sensors, barometers, and cameras to improve accuracy.
• GNSS Aiding – Periodically corrects INS drift with GPS updates when available.
