Intro

Variables

# Variables
 
| Symbol | Name                          | Description                                      |
|--------|-------------------------------|--------------------------------------------------|
| x      | State Vector                  | Represents the system’s current state            |
| z      | Observation (Measurement)     | Measured values from sensors                     |
| P      | State Covariance              | Uncertainty of the state estimate                |
| F      | State Transition Matrix       | Predicts next state from current state           |
| H      | Observation Matrix            | Maps state space to observation space            |
| Q      | Process Noise Covariance      | Models uncertainty in the system dynamics        |
| R      | Measurement Noise Covariance  | Models uncertainty in sensor measurements        |

Algorithm

Predict (Time Update)

| Equation | Description |
|----------|-------------|
| x̂ₖ⁻ = F x̂ₖ₋₁ | Predict state forward |
| Pₖ⁻ = F Pₖ₋₁ Fᵀ + Q | Predict state covariance |

Update (Observation Update)

| Equation | Description |
|----------|-------------|
| yₖ = zₖ H x̂ₖ⁻ | Innovation (residual) |
| Sₖ = H Pₖ⁻ Hᵀ + R | Innovation covariance |
| Kₖ = Pₖ⁻ Hᵀ Sₖ⁻¹ | Kalman gain |
| x̂ₖ = x̂ₖ⁻ + Kₖ yₖ | Updated state estimate |
| Pₖ = (I  Kₖ H) Pₖ⁻ | Updated covariance |