Wide Area Multilateration (WAM) Guidance Material

23 November 2011

WAM is the first distributed surveillance technique for use in civil aviation. It is modular and allows system requirements to be designed against precise operational performance requirements (for example, the service volume).

As WAM performance and coverage is specific to the local environment, and failure modes differ from other surveillance techniques, the approvals process can be unique to this technique. The on-site process is critical and special care should be taken in validating performance through operational flight trials.

The guidance notes below were created to help ANSPs and NSAs through the entire WAM implementation lifecycle, including lessons learnt from past deployments and those experienced in WAM operation. Coverage planning, changes in operations, integration into the ATC system and safety are some of the topics covered.

The material is now several years old and the guidelines are due for an update – in particular to reflect the latest legislative aspects. The material should therefore be used with this in mind.