The concept of Advanced Surface Movement Guidance & Control Systems or 'A-SMGCS' has been around for at least two decades now. But, it still represents the final frontier when it comes to air traffic management (ATM) complexity. Even if A-SMGCS deal mostly with aircraft on the ground, their contribution to safety is significant.
So, why are they so complex? First of all, the surveillance situation on the ground is not as good as in the air. With many buildings and obstructions, it is not easy to get full coverage and to know where aircraft are. Another obstacle is the way aircraft move on the ground. 'Stop-and-gos' are as common as changing direction on the spot. Going backwards is also a normal occurrence, taking place with vehicles extremely close by. Just picture a pushback tractor directly below an aircraft's belly...
Another element of complexity comes from integrating several systems: airfield lighting systems, airport operation databases — which usually belong to the airport and not the ANSP — weather sensors, and surveillance sensors for both the ground and the air. The list goes on. A-SMGCS must also know the operational context and conditions, like runways in use and whether it is low visibility or not.
Flight plans are not valid on the ground and if an A-SMGCS includes advanced features like routing and guidance, they need to know the full intentions or taxi clearances, down to every turn and intersection. Finally, safety-net features require all this information and often have very little time to react in case of alert, while minimising the occurrences of false alerts.
On top of that, add organisational complexity: quite often, airports purchase A-SMGCS as part of airfield ground lighting upgrades. But the final users on the ground are air traffic controllers who work for a different organisation...
So yes, A-SMGCS are among the most complex systems in air traffic management and require some good experience to be managed properly. With airports now purchasing their second or third generation, lessons have been learned and expertise is available. Don't hesitate to get in touch if you need support with your A-SMGCS project. Whether you are on the purchase or provision side, FoxATM can help!
Vincent
