Abstract: In the rendezvous and docking of spacecraft, GNSS signals can reflect off the target vehicle and cause large errors in the chaser vehicle receiver at ranges below a few hundred meters. It has been proposed that the additional ray paths, or multipath, be used as a source of information about the state of the target relative to the receiver. With Hubble Servicing Mission 4 as a case study, electromagnetic ray tracing has been used to construct a model of reflected signals from known geometry. O…