Item History: The Generalized Development Model (GDM) was the first military Global Positioning System (GPS) five-channel receiver developed by Rockwell Collins (then the Collins Government Avionics Division of Rockwell International). It weighed more than 270 pounds and was contained in the Air Force equipment flight test pallet and behind the seating and air conditioning pallet.
The basic resources of the system included a high-performance antenna assembly (HPAA), four RF channels connected to five single channel processors (SCP) via an 8x5 switch, a receiver processor, a data processor, an inertial assembly, a control/display assembly, an interface assembly and a bus controller. The test pallet also contained the instrumentation subsystem and power control and conditioning equipment.
History: The Generalized Development Model (GDM) program as sponsored by the Air Force Avionics Laboratory (AFAL) and was one of several user equipment programs intended to validate the feasibility and operational utility of GPS. Rockwell Collins (then the Collins Government Avionics Division of Rockwell International) designed and built the GDM system under contract to the AFAL. The primary objective of the concept validation phase (phase 1) of the GPS development program was to establish the performance limits of GPS user equipment under high dynamic conditions in an electromagnetically hostile environment. In addition, the GDM was intended to be a flexible test bed capable of emulating and evaluating a variety of alternate user equipment configurations throughout the concept validation phase of GPS. The GDM served to evaluate high anti-jam system techniques for military applications and to expand the technology base for GPS user equipment.