Radar Multipath Ghost-Target Simulator

Many "radar-tracked UFO" reports turn out to be multipath artifacts: a radar pulse that bounces off terrain, a building or a water surface before (and after) reaching a real target arrives back later and from a different angle than the direct return would. Because a radar computes range purely from round-trip travel time and bearing purely from the arrival angle, that bent path gets plotted as a second, entirely fictitious blip at a false range and bearing — a classic "ghost" or "phantom" target. This simulator implements that geometry directly with the image-source method: move the real target and a reflecting surface around a radar site and watch the phantom appear, move and vanish exactly as real radar-engineering math predicts.