1. Navigation Everywhere
   1. Sensors (Updates/Inputs)
      1. GNSS
      2. Accelerometers
      3. Gyroscopes
      4. Magnetometer
      5. Magnetic Compass
      6. Barometers
      7. Pedometers
      8. Electromyography (EMG)
      9. Odometers
   2. Fusion
      1. Kalman Filter
      2. Extended Kalman Filter (EKF)
      3. Particle Filter
      4. Monte Carlo Method
      5. Sequential Monte Carlo
      6. Markov chain process
      7. Gauss Process
      8. Bayesian inference
   3. Constraints
      1. Zero Velocity Update (ZUPT)
      2. Non-holonomic (NHC) same as Zupt but for lateral and vertical velocity