Table 3 Mathematical notation and variable definitions.

From: Advanced algorithms for UAV tracking of targets exhibiting start-stop and irregular motion

Symbol/Notation

Definition

t

Time (seconds)

\(\:{p}_{R}\left(t\right)\)

UAV (robot) position at time \(\:\:t\:\), typically \(\:{\left[{x}_{R}\left(t\right),{y}_{R}\left(t\right),{z}_{R}\left(t\right)\right]}^{T}\)

\(\:{p}_{T}\left(t\right)\)

Target position at time t, typically [x_T(t), y_T(t), z_T(t)]^T

\(\:D\left(t\right)\)

Tracking error at time t, D(t) = \(\:{p}_{R}\left(t\right)-{p}_{T}\left(t\right)\)

\(\:x\left(t\right)\)

State vector (e.g., position, velocity, acceleration) at time t

\(\:\dot{{p}_{T}}\left(t\right)\)

Target velocity at time t

\(\:\ddot{{p}_{T}}\left(t\right)\)

Target acceleration at time t

\(\:F\)

State transition matrix

\(\:Q\)

Process noise covariance matrix

\(\:H\)

Observation matrix

\(\:R\)

Measurement noise covariance matrix

\(\:z\left(t\right)\)

Measurement vector at time t

\(\:{K}_{k}\)

Kalman gain at step k

\(\:P\)

State estimation error covariance matrix

\(\:U\left({x}_{R},{y}_{R},{z}_{R}\right)\)

Potential function for UAV control objective

\(\:{V}_{max}\)

Maximum velocity of the UAV

\(\:\:{\upalpha\:},\:{\upbeta\:},\:{\upgamma\:},\:{\updelta\:}\)

Parameters in adaptive tracking filters (e.g., α-β-γ-δ filter)

\(\:IoU\)

Intersection over Union (tracking accuracy metric)

\(\:HOTA\)

Higher Order Tracking Accuracy (tracking metric)

\(\:MOTA\)

Multiple Object Tracking Accuracy (tracking metric)

\(\:IDF1\)

Identification F1 Score (tracking metric)

\(\:\:n\:\)

Number of time steps or data points

\(\:w\left(t\right)\)

Process noise at time t

\(\:v\left(t\right)\)

Measurement noise at time t

\(\:m\left(t\right)\)

Motion mode index (for hybrid motion models)