For use in aeronautics collision avoidance, satellite, automotive, and research applications
Data adaptive algorithms are critically enabling technology for automatic collision avoidance system efforts at Dryden Flight Research Center. These Dryden-developed algorithms provide an extensive and highly efficient compression capability for global-scale digital terrain maps (DTMs) along with a real-time decompression capability to locally render map data. Available now for licensing, these terrain-mapping algorithms are designed to be easily integrated into an aircraft’s existing onboard computing environment or into a smart phone application. In addition to its use within next-generation collision avoidance systems, the software can be adapted for use in a wide variety of applications, including aerospace satellites, automobiles, scientific research, marine charting systems, and medical devices.
Dryden collaborated with the U.S. Air Force to develop the algorithms, which interpret the highly compressed large area terrain maps with geographically user-defined error tolerances. A key feature of the software is its ability to locally decompress and render DTMs in real time for a high-performance airplane that may need automatic course correction due to unexpected and dynamic events. Military jets often encounter such conditions flying into and out of extreme locations. In addition, ground collisions occur all too often among general aviation aircraft, when pilots become distracted or spatially disoriented.
Dryden researchers are integrating the algorithms into a Global Elevation Data Adaptive Compression System (GEDACS) software package, which ultimately will enable users to create customized maps from a variety of data sources using a single, easy-to-use graphical user interface.
The DTM software achieves its high performance compression and decompression capability using a unique combination of regular and semi-regular geometric tiling for optimal rendering of a requested map. This geometric tiling allows the software to retain important slope information and continuously and accurately represent the terrain. Maps and decompression logic are integrated into an aircraft’s existing onboard computing environment and can operate on a smart phone application or within the limited memory and computational power constraints that typically characterize flight control and avionics computer systems. Users can adjust compression methods and error tolerances to suit evolving platform and mission requirements. Maps can also be tailored to support flight profiles of a wide range of aircraft, including fighter jets, UAVs, and general aviation aircraft.
The DTM and GEDACS software fit into the overall scheme of next-generation ground collision avoidance technology by enabling the compression of global digital terrain data into a file size small enough to fit onto a smart phone. By using improved digital terrain data, an aircraft could attain better performance. The system monitors the ground approach and an aircraft’s ability to maneuver to avoid it by predicting several escape trajectories, a feature that will be particularly advantageous to general aviation aircraft.
Conventional DTM compression techniques used aboard high-performance aircraft typically achieve relatively low compression ratios. Also, the computational complexity of decompression can be high, making them unsuitable for the real-time constrained computing environments of high-performance aircraft. In addition, implementation costs are generally prohibitive for general aviation aircraft.
The Dryden-developed software achieves its high compression ratio by intelligently interpreting its maps rather than requiring absolute retention of all data. For example, the DTM software notes the perimeter and depth of a mining pit but ignores contours that are irrelevant based on the climb and turn performance of a particular aircraft and therefore does not waste valuable computational resources. Through this type of intelligent processing, the software eliminates the need to maintain absolute retention of all data and achieves a much higher compression ratio than conventional terrain-mapping software. The resulting exceptional compression capability allows users to store a much larger library of DTMs in one place, enabling comprehensive map coverage at all times.
Additionally, the ability to selectively tailor resolution of geographical details enables high-fidelity sections of terrain data to be incorporated seamlessly into a map. The software’s real-time decompression capability makes it well-suited for use in aeronautics, marine charting and warning systems, missile guidance, geospatial information systems, and other types of terrain and geographic software.
Dryden is pursuing patent protection for this technology.
This technology is part of NASA’s Innovative Partnerships Office, which seeks to transfer technology into and out of NASA to benefit the space program and U.S. industry. NASA invites companies to consider licensing the Global Elevation Data Adaptive Compression Algorithms (DRC-009-008) for commercial applications.