Trajectory ambiguity for active sensors

Trajectory ambiguity for an active sensor is discussed in the context of a linear time-varying channel. This type of ambiguity representation preserves details of target/channel behavior that are lost in a correlative ambiguity function representation. The trajectory diagram, which is a graphical view of radar and sonar, is used to motivate the discussion. Ambiguity manifests as sets of ambiguous target trajectories: different range versus time profiles for a target that produce identical received signal phase. These trajectories provide a "trajectory domain" picture of ambiguity that is useful for signal analysis and signal design.