The development and implementation of a local Space-Based Augmentation System (SBAS) for satellite navigation systems would greatly benefit the South African aviation sector, a cost/benefit analysis has found. Such augmentation systems increase the accuracy of satellite navigation systems, which are vulnerable, for example, to interference from the ionosphere.

"We're looking at about 7 000 aircraft across South Africa -- commercial, business aviation and general aviation," cited ND Consult director Dr Nina Costa, who carried out the study. She was speaking at a South African National Space Agency seminar on SBAS, in Pretoria, on Thursday. "Aviation will benefit enormously from a South African SBAS."

She calculated that, over a 30-year period, the accumulated quantifiable, undiscounted benefits for the whole South African aviation sector would come to some R6.23-billion while the costs would be around R1.17-billion. In discounted terms, the sector would still deliver benefits that would exceed costs by around R200-million. "Of course, the benefits and costs have different timings!"

The quantifiable benefits include increased operational efficiency and improved routing allowed by the greater precision provided on aircraft positions. The costs are the equipping of aircraft with the SBAS equipment, the implementation of the requisite procedures and training at airports, the deployment of the ground infrastructure and the operating and maintenance costs. Moreover, it would provide "integrity", showing, at any time, whether the satellite navigation system could be relied on or not (for example, in the case a satellite malfunctions).

However, there are also unquantifiable benefits. One is increased safety, including for  general aviation. Another is the possibility of opening of smaller airfields, currently limited to good weather daylight operations owing to a lack of sophisticated instrumentation, to regular scheduled flights (using the great accuracy of SBAS to allow aircraft to safely operate in more adverse conditions). The Civil Aviation Authority of South Africa has estimated that there are some 15 to 20 airfields in South Africa in this category.

Furthermore, there is also the potential of a SBAS to stimulate industrial and economic growth. This could happen both through stimulation of aviation operations and through application of the technology to other sectors. SBAS technology is also applicable to precision agriculture, road and rail transport, ports and maritime operations, asset tracking and infrastructure construction, among others.

Because a local SBAS would be safety critical for the aviation sector, it is likely that it would be operated by an aviation agency, such as Air Traffic & Navigation Services. For a variety of reasons, South Africa cannot simply be covered by an extension of an existing SBAS developed and deployed by Europe or the US, and must deploy an independent system, although this will use proven technologies.