The Four Dimensional Weather Data Cube, or 4-D Wx Data Cube, is a virtual data repository that provides its users access to weather information distributed among a wide variety of sources. While each source retains possession of its weather data in standard formats, the Cube serves as a sort of data moderator, filtering the aggregated data for the 'best' information available and relaying it back out to users. In this way, all users — including contributors to the Cube — have access to the most authoritative, up-to-the-minute weather observations and forecasts available, without forcing a single file system to host all the data.
In the diagram below, each of the colored cubes represents one or more databases hosted by the National Weather Service (NWS), the Department of Defense (DoD), the Federal Aviation Administration (FAA), the National Oceanic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA), and other, commercial data vendors. The most accurate data from each of these sources (the smaller, semi-transparent blocks) are 'stored' by the 4-D Wx Data Cube's virtual database in the center. While the data remains on the external systems, users can access the centralized weather picture the Cube provides.
The "4-D" in the term "4-D Wx Data Cube" refers to the weather data itself. A particular location's weather forecast is stored with four key pieces of information, one for each dimension. The three spatial dimensions are, of course, used to log the forecast's location — longitude, latitude, and altitude. The fourth dimension, time, is used to log the period over which the given forecast takes place. Thus, a piece of weather forecast data contains a given location's change in weather over a period of minutes or hours.
Though the 4-D Wx Data Cube will virtually contain all the available weather-related information shared by its contributors, not all of the Cube's users will require access to the same data. As such, the Cube will be broken into a series of data domains, each of which will have different access rights.
The bulk of users, looking to make air traffic management decisions in civil airspace, will have access to the Single Authoritative Source (SAS): the Cube's chief data domain for current weather observations and both short- and long-term forecasts. The remaining domains are divided between those with open, unrestricted access rights and those containing proprietary data, which consequently have limited access rights. The diagram below visually represents how the data available in the 4-D Wx Data Cube is divided between restricted and unrestricted domains.
Domain 1 – Known as the SAS; used by NAS operators (e.g. air traffic controllers) to make decisions in civil airspace. Open data rights.
To better understand NNEW's development of the 4-D Wx Data Cube, it is helpful to have a firm grasp of the Cube's foundational technologies. The following articles provide introductions to those technologies and describe how each relates to NNEW's Cube:
- Service-Oriented Architecture
- XML and XML Schemas
- The role of relational databases in weather data dissemination
- Entity-Relationship (ER) Modelling
- Unified Modelling Language (UML)
- Geography Markup Language (GML)
A Note on Perspective
The Joint Planning and Development Office (JPDO), itself a coalition of seven government agencies, has assigned two of its participating agencies the task of developing the 4-D Wx Data Cube. The National Weather Service is working on behalf of NOAA to build one portion of the Cube, while NNEW was formed by the FAA to built the other portion. All information available on this wiki deals with the FAA's portion of the Cube.
|NextGen and NNEW|
|The 4-D Wx Data Cube|
|XML and XML Schemas|