After initial acquisition, what must a contact do to be considered valid for tracking?

• A. It must meet initiation criteria: consistent motion (range-rate and bearing change), persists across several scans, and fits the track gate.
• B. It must be within a fixed distance from the radar and have a stable brightness.
• C. It must be a larger than a threshold size and have a constant range.
• D. It must be detected in at least one scan and immediately assigned a track.

Answer: (D)

After initial acquisition, turning the detected contact into an active track is what allows continued monitoring. The required step is that the contact is detected in at least one scan and immediately assigned to a track. This creates a track object that can be used for prediction and subsequent updates, so the system can fuse future measurements and maintain orientation to the target.

The other ideas describe criteria used to validate or refine a track over time (such as motion consistency across multiple scans or gate fitting, or thresholds on distance, brightness, or size). Those are about confirming or filtering tracks, not the immediate action needed right after acquisition to make the contact trackable.