In 1996 CAST entered into an exclusive arrangement with both Honeywell and Litton (now known as Northrop Grumman) to develop a system that allows for the integration and test of their respective tightly coupled GPS/INS navigation systems (EGI’s). We called this system the Embedded GPS/INS Tester (EGIT). This original arrangement included the H764G (Honeywell) and the LN-100G (Northrop Grumman) units. Since then this arrangement has been expanded to include the GGP (GPS Guidance Package), HG1700 IMU and NAV100 products produced by Honeywell as well as the GGP, LN200, LN25X and LN260 navigation units that are produced by Northrop Grumman. CAST has worked very closely with both Honeywell and Northrop Grumman to assure that inertial modeling and timing of the CAST EGIT has been thoroughly tested and validated.