|Acronym:||4-D Wx SAS|
|Name:||4-D Weather Single Authoritative Source|
|Description:||The 4D Wx SAS is a subset of the 4-D Wx Data Cube and contains horizontally and vertically consistent data. Single values for each of the observed, analyses, and forecast conditions for aviation-related weather parameters (or phenomena) are available for every gridpoint to include forecast increment times. For example, the 4-D Wx Data Cube will contain forecasts from multiple forecast models, some of which may show better prediction "skill" than other models in certain weather situations (e.g., pop-up thunderstorms). The 4-D Wx SAS will contain the resulting "consensus" forecast--the "common weather picture." In addition, the spatial and temporal requirements for the weather information at each gridpoint will vary based on requirements as specified by the civil [FAA] ANSP for NextGen ATM decision-makers. For example, forecasts of convective weather will be updated more often than forecasts for space weather. Information/data from commercial providers may be identified as 4-D Wx SAS data provided the Government obtains the appropriate data rights.
At FOC, the 4-D Wx SAS has the following characteristics and assumptions:
* Includes current observations and analyses (or interpolations) of current conditions, and predictions of future weather conditions
* The weather state grids are internally consistent regardless of which weather parameter is being considered
* Contains only weather state of the atmosphere information; aviation impact information is in a separate non-weather Cube
* Contains no manual forecasts or legacy weather products (current products stipulated by the International Civil Aviation Organization, such as observations and advisories, will be renderings or displays external to the 4-D Wx SAS, created from the data pulled from the 4-D Wx SAS)
* Government-produced weather data/information to meet regulatory requirements is entirely within the 4-D Wx SAS
* A single set of grids yields information to support CDM decisions
* Includes probabilistic forecasts to support risk assessments and decision-making
* Will be available to all ATM decision-makers as a network-enabled part of the 4-D Wx Data Cube.
In the NextGen era, DSTs will ingest 4-D Wx SAS weather information for integration with non-weather information to determine operational impacts and associated risks based on the user-established business rules and specific aircraft operating parameters. User DSTs enable enhanced risk management and will help mitigate weather impacts to NAS operations. For example, the Traffic Management Advisor is a user DST that will integrate digital forecasts of potentially impacting weather associated with convection with wind information to enable improved merging and sequencing of aircraft onto the runway.
Additional details of the 4-D Wx SAS are available from the '4-D Weather Functional Requirements for NextGen Air Traffic Management', the NextGen Concept of Operations (ConOps) v2.0, the NextGen Weather ConOps v2.0, and the NextGen Weather Policy and Recommendations v0.1.
|NAS Hierarchy Element/Sub-Element(s):||None|
|Phases of Flight:||None|