What is GPS rover? and what are its modules?

Remotely Operated Video Enhanced Receiver (ROVER), a GPS rover is simply a ROVER system that utilizes GPS.

"The initial ROVER system, ROVER I, was developed in 2002 to allow ground forces to view video feeds from Predator UAVs or AC-130 gunships. The interface was so large it was carried in a Humvee, but it avoided the long delay of having to call a distant UAV controller and ask what the aircraft was seeing. By fall of 2004, the system's size was reduced to that of a 12 lb device carried in a backpack. ROVER IV plans to include the capability to interface with a wide variety of aircraft and also allow interaction between ground controllers and close air support pilots. With ROVER III, ground controllers have to talk the pilot to the target since they only see the image the aircraft transmits. ROVER IV seeks to use GPS and other systems to allow the controller to click a target they would like the aircraft to engage or the UAV operator to focus on. ROVER is compatible with UAVs and aircraft carrying the LITENING targeting pod as well as other targeting systems."

A rover is a receiver (such as a GPS receiver) that collects data at remote locations. The rover's position may be recorded or computed relative to another reference source (such as a fixed GPS receiver).

Modules would include everything from HD cameras to IRDFS uplinks