Today, the Meteorological Services for Air Transport involves information flows that are increasingly complex and made up of interconnected systems. The flows involve many actors including multiple suppliers and consumers.
The primary function of the Air Traffic Management system is to enable flight from an aerodrome into airspace and its subsequent landing, safely separated from hazards, within capacity limits and making optimum use of all system resources. It is clearly evident that this ATM system needs to be a network-based operation formed by four main components. These components will dramatically increase the efficiency of the system:
- A robustly networked ATM System will improve information sharing
- Information sharing will enhance the quality of information and provide shared situational awareness
- Shared situational awareness will enable collaboration and self-synchronisation
- Deliver enhanced sustainability and speed of knowledge based decision making
In pursuit of this ambition, the meteorological (MET) communities are moving from product-centric operations to data-centric operations.
Each airport and each aircraft being considered as a node interlinked with all others within the system. The availability of timely, high quality information will provide a foundation for effective management of this networked system. Nevertheless, the system will continue to be subject to the effects of uncertainty, especially from adverse weather.
The use of MET information in a data-centric environment and satisfying the foreseen performance requirements for MET will have an impact on the information that needs to be made available and exchanged between information providers and users. This exchange should not only be interoperable from a MET information perspective but also clearly interlinked with other data domains that are relevant for ATM.
ATM systems, such as controller decision support tools, will not only use MET information but will fuse this information with other relevant information such as Aeronautical Information (AIM) and Flight Information to support knowledge based decision making. MET information should therefore be structured in accordance with generic ATM information management principles applicable to all data domains.
Weather Information Exchange Models
The Weather Information Exchange Model specifications support the data-centric environment. It supports MET information collection, dissemination and transformation throughout the data chain.
It has three main components:
- The conceptual Information Model (WXCM)
- The Logical Data Model (WXXM)
- The Exchange Schema (WXXS)
When the 3-tiered model (WXCM-WXXM-WXXS) is referred to as a single entity, the term used is 'WXXM'.
The conceptual Information Model (WXCM) is a high level conceptual model of the MET domain. It provides a view of the concepts and packages (e.g., ICAO Annex 3, ISO 19100, WMO BUFR tables), that make up the data model. In this data model, this layer is represented using a combination of plain text and UML package diagrams. This layer is implementation independent.
The Logical Data Model (WXXM) fully describes the exchange model associated with the information model, in an abstract form. In this data model, the logical model is represented using UML. This tier is implementation independent, capable of supporting multiple physical representations.
The Exchange Schema (WXXS) provides a mapping of the logical data model to a physical representation. This layer is represented using XML Schema, and is implementation-dependent. The geospatial aspects of the WXXS are implemented using Geography Mark-up Language (GML) version 3.2.1. By conforming to the GML Specification, it is intended that the WXXS datasets will be compatible with third-party GML-compliant applications, and hence enable aeronautical users to reap the benefits of open Geographic Information Systems (GIS) standards.
Uses and Benefits
The WXCM-WXXM-WXXS family of models and schema brings many benefits to the user, when moving from product-centric operations to data-centric operations.