Which brevity term indicates an object has been acquired and is being tracked with an onboard sensor?

The term that indicates an object has been acquired and is being tracked with an onboard sensor is "Track." When a unit reports "Track," it communicates that they have established a clear track on the target using their onboard sensors. This term implies active monitoring and an ongoing assessment of the object's location and movement, which is critical in fire support operations for precision engagement. It demonstrates a continuous acknowledgment of the target's presence and position, ensuring that any subsequent actions can be coordinated effectively.

In contrast, the term "captured" typically refers to a situation where a target has been successfully engaged or neutralized, while "spot" suggests that a target has been visually identified but not necessarily being tracked with sensors. "Contact" is a broader term that indicates the presence of a target but does not imply that it is actively being tracked; it simply denotes that a unit has noted something of interest. Therefore, "Track" is the most accurate term to describe the active tracking of an object with onboard sensors.