Which spotting indicated when a round's location cannot be determined by sight or sound?

The correct response is the term that refers to a situation where the impacts of a round cannot be seen or heard. In field operations, the term used for this scenario is "Unobserved." This term indicates that the observer cannot directly confirm where the rounds landed due to factors such as visual obstructions, distance, or environmental conditions affecting sound propagation.

"Lost" typically means that the observer has lost track of the mission or the effectiveness of the rounds for some reason, such as having a compromised ability to engage targets but does not specifically address the inability to see or hear the round's landing.

"Not Applicable" suggests that the situation does not fit any defined criteria, which is not the case here since a clear definition exists for when a round's location is unobservable.

"Misidentified" would indicate that the observed information about the rounds or targets was incorrect, affecting targeting decisions, but this does not pertain to the situation of being unable to determine the round's location due to lack of sight or sound.

Understanding these terms is crucial for effective communication and coordination in fire support operations, allowing teams to act upon the situation appropriately, even when direct confirmation of impacts is unavailable.