CIDD Introduction and Overview

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The display software, CIDD (Configurable, Interactive Data Display), is primarily intended as a display system for real-time meteorological data. It also provides capabilities for archival data display as well as a mode whereby it outputs imagery for Web page integration. It runs on a wide variety of Unix workstations using X-Windows graphics. Its principle function is to integrate and display, in real-time, meteorological information from disparate and distributed sources. It combines visualizations of gridded data along with other products (data) displayed as symbols or text, overlaid with maps and other geographical symbols. Graphics on the display are automatically updated as new data arrives, and movie loops shift forward in time as time passes. The display's user interface is designed to be operated without extensive training or reference to detailed operators manuals.

The architecture of the display and its data servers are flexible and modular, allowing for easy integration of new data and its configuration for a variety of locations and classes of users. Its client-server design allows a wide variety of distributed storage topologies and its http access modes allow for the tight integration with HTML based data visualization. The user interface can be configured to display just the minimum set of controls necessary to perform a task or can be configured to allow access to all the controls over product combinations, colors, contour intervals, etc. This allows the same software to be used by both non-technical personnel with little or no training, as well as highly technical users who want to customize the imagery and explore the data in a variety of ways. CIDD's windows can be resized or closed on the screen, making it compatible with other tools the user may wish to run on the display workstation.

Gridded data can be visualized in a variety of ways; as color-filled rectangles or trapezoids, in the case of radial data, as color filled-contours and open contours. Wind fields may be displayed as wind barbs, with or without labels or scalable vectors. Data from grids of differing sources, resolutions or positions can be viewed simultaneously, being automatically registered correctly onto the same image.

The imagery can be animated to form movie loops of products over time with the display automatically updating the animation loop as new data arrives. Non-gridded data such as pilot reports, meteorological station reports, or hazard areas, are displayed over the gridded products as colored lines, text, or iconic symbols and can be displayed and updated during animation.

Users can select from a set of preset geographic domains or can arbitrarily zoom over any region of the display. As the user zooms in, additional detail in wind vectors, geographical overlays and symbolic products are revealed. This feature prevents the display from becoming crowded with too much graphics when viewing a regional area, yet allows the user to see all of the available information when viewing a limited area.

Users may arbitrarily select a multi way point route, using the mouse, for viewing vertical cross sections of the gridded data. The cross sections are constructed on demand and can be animated along with the main plan view imagery. Contours, and sets of wind vectors based on gridded data, can be overlaid on top of the cross sectional data grids.

CIDD uses a flexible client-server mechanism to retrieve its data for display. Data are served to each user's workstation via TCP/IP network protocols as the user requests different products or shifts their temporal focus. Facilities for tunneling the data requests through http proxies and the Apache http server can be added to enable access to data through fire-walls. The client server architecture and protocols allows the display to operate over both high bandwidth and low bandwidth networks or PPP links.

CIDD's client-server data access mechanism is flexible and configurable. Data distribution topologies can be set up to allow users access to data that cannot be transmitted in their entirety down low bandwidth or transiently connected networks. Data can be automatically pre-distributed to sites which have higher speed networks and whose users need rapid access to large data sets.

CIDD supports RAP's fault tolerant mechanisms in situations where the display will be used continuously for long periods of time. CIDD produces a heartbeat which can be monitored for anomalies and restarted if necessary. CIDD has run for months at a time without restart in unattended settings, serving operations center personnel.

The Displays main features include:

• Easy to learn X based User interface - Supports 256 color and 16/24bit True-color Modes.
• The most commonly used features are controllable from the main window or keyboard.
• Integrates data from different sources and projections into one image.
• Automatically updates imagery with as new data arrives.
• Unlimited number of animated frames in loops.(Dependant on system memory available)
• Predefined or Arbitrary Zoom on plan view displays
• Arbitrary selection of cross sections via simple mouse actions.
• Animation Speed and end of loop delays are user adjustable.
• Displays up to 6 gridded fields simultaneously, layered over one another.
• Overlays Contours of gridded data with user selectable intervals and color.
• Overlays multiple sets of wind barbs or scalable vectors.
• Users may select/De select and change the color of geographic overlays.
• Font sizes and line widths are adjustable for contours and symbolic products.
• Built in range rings and azimuth overlays with increasing detail on zooms.
• Gridded data can be easily dimmed on 8 bit displays to enhance and clarify complex overlaid products.
• Archival data can easily be accessed and displayed.
• Distributed data model allows users to run the display from their desktop.
• Config files, maps and color scales may be stored and accessed on a HTTP server.

CIDD Can:

• Display data arrays collected in either rectangular or spherical polar coordinates. Rectangular and polar data can be displayed simultaneously on a Modified Mercator, Lambert Conformal, or Local Area Cartesian projections. CIDD can display geographical maps, contours, wind vectors or barbs and well as other data depicted as lines, symbols, text and icons.
• Define and display vertical cross sections along arbitrary multi way-point routes.
• Be used to draw simple lines and polygons for output to other algorithms and displays. For example, CIDD can be used to draw an area boundary for severe turbulence, and then distribute this warning to other users in real-time.
• Run on UNIX X based workstations using 8 to 32 bit depths.
• Be use for Real-Time and Post Processing Modes of operation.
• Automatically gather data from distributed databases via client-server mechanisms. This facility allows the display to run on any desk top workstation. All displays can share the same data sources and archives, preventing the duplication of data sets and large data transfers.
• Allow users to interactively configure which data will appear on their display, what geographical area the display will cover, and over what time periods.
• Display arbitrary vertical cross sections selected by pointing and dragging. Data field selection for horizontal and vertical views are independent.
• Can Zoom and Area Move its viewable domain, selected by clicking and dragging.
• Overlay multiple data grids onto one another selectable range transparency, as well as display contour and wind vector overlays.
• Generate Movie frame sequences that span over 8 hours. Movie sequences are not stored but are built "on the fly". Data with differing time granularities are accommodated.
• Display both real time products and archived products.
• Export lat-lon coordinates to external programs. CIDD uses a shared memory area which allows external programs to read coordinates (Latitude, Longitude, Altitude and X,Y,Z km, and data time) from the display. Current ancillary programs which make use of this interface include: time_hist; a storm cell analysis tool, pos_report; A position finder, for reporting relative distances and headings, snow_graph; which displays precip accumulation rates over time, gauge_strip; shows time histories of mesonet data closest to the click point, winds_select; a tool which plots a tabular vertical profile of model data, metar_select; which displays a table of the metar data nearest the user selection, and cidd2skewt; which generates synthetic skewt's from model data.
• Automatically generate graphics for Web based delivery. Cidd can be configured to automatically cycle through all of its data fields, heights, zoom domains and forecast times, producing huge numbers of images.
• Use a Remote User Interface mechanism to specify and generate output imagery. A simple command set has been established which allows script and CGI based mechanisms to specify and drive CIDD to output images. This feature is currently being used to deliver custom route cross sections, generated on-the-fly and delivered via web pages.

CIDD Cannot:

• Satify everyone.
• Run natively on Microsoft OS'es (Use VNC or Vmware)
• Display more than one plan view at the same time (One can always run multiple CIDDS)
• Display Profiler Data (Other programs do this)
• Display Sounding Data (Other programs do this)
• Display data not on a Mercator, Lambert tangential, or Radial projection.

CIDD To Do's

• Use a more powerful configuration mechanism to define exactly how each page of data appear.
• Provide a run-time editor panel for the above mechanism
• Add support for other common map projections.