What is a track gate in radar tracking?

• A. A hardware device that filters out weak signals.
• B. A track gate is a defined region around a predicted track used to accept or reject detections.
• C. A track gate is a hardware switch that opens the radar transmitter.
• D. A track gate is an alignment device for the antenna feed.

Answer: (B)

A track gate is the defined region around the predicted position of a target used to decide which detections belong to the current track. After estimating where the target should appear next, the tracker draws a gate—often an ellipse or circle—whose size reflects the expected measurement and motion uncertainty. Detections inside the gate are accepted to update the track, while those outside are ignored for this track (or may trigger a new track). This gating helps keep the track consistent by reducing clutter and preventing false associations. The other options describe hardware or front-end functions, not the data-association process in tracking.