Which of the following is NOT a characteristic used to describe target signatures?

Power is not typically considered a characteristic used to describe target signatures in direct fire engagement. Target signatures generally include observable and identifiable features that help in the detection and classification of targets. These features are assessed through various sensory inputs.

Sight involves the visual identification of targets, which can include size, shape, color, and movement. Sound refers to auditory signals, such as noise generated by the target or its surroundings, which can offer clues about its presence. Smell may sometimes be relevant, particularly in close combat situations, where certain odors can indicate the presence of personnel or materials.

In contrast, "power" does not fit as a direct characteristic used for identifying or characterizing a target's signature. While power can be associated with some military equipment or weapon systems, it is not a sensory characteristic that would typically inform a target's identification on the battlefield.