Description: This proposal introduces an innovative sensor concept for the mitigation of aircraft hazards due to reduced visibility in fog, drizzle and light rain and the detection of hazards/obstacles on runways. Specifically, this effort will build upon a developing synthetic vision system for landing piloted aircraft to: 1) customize the design and feasibility for targeted unpiloted autonomous systems (UAS), and 2) incorporate interferometry for terrain mapping and hazard detection. Dubbed "PathIn", the proposed sensor is comprised of a Ka-band digitally beamformed (DBF) radar interferometer that will serve as a complement to existing infrared (IR) and near-IR enhanced visualization systems and provide a real-time data interface for ground-collision avoidance systems. The proposed effort is aligned with the effort to integrate UAS into the National Airspace (NAS). The Phase 1 effort will assess the PathIn performance for sample UAS flight scenarios over variable terrain using a high-fidelity point target simulator to provide synthetic digital surface maps and obstacle detections. This will demonstrate the potential of the PathIn as a technology that can contribute toward safe UAS operation in the NAS and in the terminal area. In Phase II we will realize a prototype of the PathIn sensor, leveraging our extensive radar, interferometry and DBF experience and key technology capabilities. In particular a FPGA-based digital receiver system will be extended for real-time beamforming and interferometry. At the end of the Phase I, a technology readiness level of 3 will be achieved.

Benefits: NASA's expanded reliance on UASs has dramatically increased the need for alternative airports to support mission scheduling. Limited available airports meeting FAA landing restrictions will have a more profound impact on mission planning, success and cost as longer duration aircraft use is increased. Challenges include low visibility conditions and the difficult scenario of long duration mission planning with weather forecasting uncertainty. With the capability of obstacle detection, RSS' proposed PathIn system would allow for the use of airports not previously acceptable, and do so during conditions such as fog and drizzle, which conventional infrared enhanced vision systems cannot provide adequate visibility through. By providing "improved sensing capability in the terminal area where higher density and more reliable operations are required for NextGen" this sensor stands to directly support NextGen.

Low visibility conditions during aircraft landing presents significant hazards to the commercial and defense sectors. The need for a capable EFVS technology, the PathIn system in particular, has been expressed to RSS by large commercial entities such as Telephonics Corporation and Gulfstream Aerospace. RSS has investigated the early commercial market for the PathIn system, which is estimated at 500 units or $450M at the outset for Gulfstream alone. DOD & DARPA agencies heavy reliance on UAVs, requiring all weather landing capabilities for successful mission execution, has increased as well. Initial conversations with Army representatives yielded similar interest as with commercial entities. As part of the Phase I effort, RSS will seek to include the requirements of these organizations such that the resulting PathIn system meets their needs.