If the receiver has some internal sensors that can also help (gyros of various kinds).
I remember as a kid my father was working on the first version of the Air Combat Maneuvering Range (this was back in the late 1960s.) This involved dogfights with simulated missiles and guns. To work, the system needed to accurately track the position of the aircraft. Radars on mountains around the range would give good positions in two dimensions, but poor vertical position (this axis was nearly perpendicular to the line from a radar to a plane). The solution was to add a pod to each aircraft with various gyros and incorporate this information via a Kalman filter. Nowadays such a system would just use GPS, much simpler.
I remember as a kid my father was working on the first version of the Air Combat Maneuvering Range (this was back in the late 1960s.) This involved dogfights with simulated missiles and guns. To work, the system needed to accurately track the position of the aircraft. Radars on mountains around the range would give good positions in two dimensions, but poor vertical position (this axis was nearly perpendicular to the line from a radar to a plane). The solution was to add a pod to each aircraft with various gyros and incorporate this information via a Kalman filter. Nowadays such a system would just use GPS, much simpler.