Abstract: The methods and systems relate to tracking targets, and more particularly to tracking multiple targets within a field of densely distributed sensor nodes using wave processing/analysis methods applied to “target-waves” in an observable physical phenomena. The “target-waves” are target induced perturbations of a physical phenomena that are analogous to a propagating wave where the wave propagation velocities are equal to the target velocities. The term “target” refers to an individual object, or a group of objects that can be treated as an entity, whose position, speed, direction, separation, etc. is of interest to a user. Some examples, not exclusive, are military vehicles (e.g. tanks) along a road, people on sidewalks or in halls, and ships at sea.