ATM Modernization, Business & GA

Editor’s Note: Synthetic Vision: The Next Step

By Charlotte Adams | October 1, 2006

Synthetic vision technology, as this issue of Avionics Magazine points out, is transitioning from general to corporate aviation. It's only a matter of time before bizjet operators usher the technology into everyday use. What will they get for the investment? Although lower minimums are high on everyone's wish list, the immediate promise is heightened short-term situational awareness, which in itself is worth a great deal.

Backed by high-resolution terrain data and the latest in graphics processing, synthetic vision systems (SVS) are able to present a virtual, clear-sky view of landscape, obstacles and runways ahead of the aircraft regardless of weather or visibility conditions. This real-time-updated, virtual environment can be overlaid on the primary flight display (PFD) and used in combination with flight and navigation information. As Gulfstream, the first business aviation airframer to announce an SVS certification project, asserts, synthetic vision technology will help pilots make tactical decisions faster and more accurately, increasing the safety of flight.

Gulfstream's SVS is based on Honeywell technology. In addition to Honeywell, Innovative Solutions & Support is developing an SVS product, which it plans to introduce to bizjet customers next year. Universal Avionics obtained a supplemental type certificate (STC) for its Vision 1 SVS product on a Bombardier Challenger 601 aircraft in May 2006. Rockwell Collins continues to refine its synthetic vision technology, although no customer has yet been announced.
The enhanced ground proximity warning system data set underlying Honeywell's SVS is not intended for navigation, as the company is the first to say. But even so, synthetic vision on the primary flight display, when combined with flight path vector symbology, can add a powerful tactical flight management tool. It might pay for itself rapidly in busy terminal areas and on challenging instrument approaches.

But what is needed for synthetic vision to play more than an advisory role? Adopters of synthetic vision technology in high-end business aviation and (eventually) commercial air transport will want to achieve quantifiable operational benefits in return for their investments, just as they were able to accomplish with imaging sensor-based enhanced vision system (EVS) technology, which now permits lower minimums for Cat I approaches.

Many areas of potential operational benefit are under consideration. Could some form of SVS technology allow taxi operations when some taxi lights are unavailable? Could it substitute for some approach lights in serving as a runway identification and line-up reference? Could an operator get lower minimums on an approach because the pilot can "see" an image of the terrain around the airport and the outline of the runway? As FAA officials stress, it's really impossible to say until they see what industry brings to the table, what the technology's capabilities are, and how the operator intends to use it.

While synthetic vision is independent of the external environment, it is highly dependent on the aircraft's navigation solution, terrain, obstacle and runway databases, and on the hardware and software employed to generate the images.

One of the areas researchers are looking at as part of an approach to increase synthetic vision's utility involves real-time verification of the integrity of SVS data. NASA, in its now-completed Aviation Safety and Security program, experimented with real-time database integrity monitoring, using sensors such as weather radar, altimeter and bistatic GPS radar to compare stored SVS data with data collected in flight from the real world.

The conclusion was that the idea of real-time database verification is plausible and could help with the integrity issue. But many questions remain. NASA is continuing to investigate real-time data integrity monitoring-this time including all cockpit data-in a follow-on program that is just beginning.

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