What is the meaning of the sensing term "Lost"?

The term "Lost" in a sensing context specifically refers to the inability to identify a target. This indicates that the system or personnel responsible for tracking or observing the target no longer has sufficient information or data to determine its identity. This could happen due to various reasons such as loss of communication, interference, or other operational challenges that may affect target identification.

A target being identified would imply successful recognition or establishment of its characteristics, which stands in contrast to the meaning of being "lost." Similarly, if a target were not within range, it would suggest a limitation in detecting the target due to distance rather than a lack of ability to identify it. Moreover, if the target direction is uncertain, that would indicate some level of tracking capability still exists, but clarity about the target's identity is not attained—this does not align with the definition of "lost." Hence, the correct interpretation of "Lost" directly points to the inability to identify a target.