Radar target tracking can be presented as combination of track filtering and association algorithm, where association problem is to determine validity of observation-to-track pairing. Track represents single real object build as set of observations connected together using association process. To eliminate unlikely observation-to-track pairings association algorithms employ gating techniques. Using track filtering results, a gate is formed, as a constricted space around tracked object predicted position. This space is called tracking gate and all observation that fall within the gate are considered for the track update. In this paper analysis of tracking gate shape and behaviour is investigated, with association gates build using Kalman filtering and Mahalanobis distance as a metric. Results are presented as graphical spatial imaging of tracking gates, for simulated tracking data considering different manoeuvring scenarios and tracking filter parametrisation.