GPS Portable Landing Aid System for Tiltrotor Aircraft

The proposed GPS Portable Landing Aid System (GPLAS) provides a highly accurate, fully autonomous system that is ideally suited to support V-22 missions. The GPLAS ground station includes a GPS reference receiver (RR) and a pseudolite (PL) which broadcasts the landing signal and GPS data corrections to the aircraft. The RR also is used to automatically survey the landing site. Since the PL signal is in the same format as the GPS satellites, the GPS receiver on-board the aircraft can be used to provide precision guidance throughout the approach. The spread-spectrum nature and low power of the PL signal guarantee a low probabilty of intercept (LPI), which is essential for covert applications. NAVSYS is currently under contract to ARPA to build a prototype GPS autolanding systems suitable for UAVs. Under the proposed Phase I efforts, the operational and performance requirements for a PLAS system will be identfied to take full advantage of the V-22 insertion and extraction capabilities. A study will be performed of the best method to integrate the GPLAS with the aircraft and design the ground equipment in support of SOF missions. Under Phase II, a prototype GPLAS will be built and flight tested.