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  Hungarian Meteorological Service  founded: 1870
Research and development | Numerical Weather Prediction  | Analysis of the Atmospheric Environment | 
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The HAWK-2 meteorological visualization system

HAWK-2 (Hungarian Advanced WorKstation) is a visualization system developed and used by HMS (Hungarian Meteorological Service), that allows the forecasters to systematize and view the wealth of meteorological information that is available in their daily work. The software can display meteorological data over maps and on special diagrams (e.g. emagram). Its advanced visualization functions make it an efficient tool for overviewing meteorological processes and numerical forecasts.

HAWK-2 operates on HP-UX and Linux platforms, uses the X Window system and OpenGL for graphics. The software is written in an object oriented way in C++. The graphical user interface is made using Motif. The software can only visualize the special data files used in HMS, that are mostly in the netCDF (network Common Data Format).

HAWK térkép
Visualisation of numerical weather prediction fields in HAWK-2

Main features of the HAWK-2 meteorological workstation

The graphical user interface has 4 or 5 panes, that can be configured independently and may contain any meteorological field.

The software is able to display and print any combination of surface observations, radiosonde measurements, radar and satellite images, or numerical forecasts.

It is possible to step through the loaded data fields and create animations. The contents of all panes can be synchronized to show the same point in time, during time stepping or animations. The software can automatically update the displayed fields (e.g. when new observations arrive).

For all display types it is possible to save and load the visualization settings (menus), and also to define and use macros to specify the kind of information in each pane. Each user can have a separate menu and macro set.

The software can display meteorological data over maps, on emagrams, and as spatial and temporal cross sections. For maps and emagrams, the user may zoom in on the image. A great number of maps can be used, with interactively displayable map elements (borders, coastlines, rivers, lakes, etc...). It is possible to colour the land and sea differently, and also to use orographic relief background images.

With the scanning function, the exact numerical values of the displayed fields at the position indicated by the mouse, can be displayed.

Fields from numerical weather prediction models can be displayed in 3D.

At any time, the user may print the contents of the screen, or send the image via email.

The software is not only a passive display system; with the front analysis tools, the user can create, view, and modify a complete front analysis map.

 

Data types displayed by HAWK-2

Numerical forecasts are usually available as data fields over a regular geographical grid. They can be visualized in a number of ways:

On a map background

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As isolines, or filled iso-maps

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By windbarbs or wind vectors

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Using weather symbols

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As spaghetti diagrams (ensemble products)

As spatial, vertical cross sections (over an interactively defined line)

As meteograms

As a 3D display of iso-surfaces

Radar imagescan be displayed in 3 ways:

Over map backgrounds

As a special range-height (RHI) diagram, that displays the reflectivity values in a given vertical plane

On a vertical azimuth display (VAD)

Radar image over map backgrounds Special range-height (RHI) diagram Vertical azimuth display (VAD)

Satellite images are displayed over map backgrounds. Besides the traditional one channel images, hawk can display coloured composite images as well.

Visualization of surface observations (SYNOP) is done over a map background, using conventional meteorological symbols and numerical values.

Upper-air observations (Radiosonde measurements) can be displayed either over a map background or as emagrams. The program calculates a number of stability parameters, and it can create hodographs.

Lightning localization systems provide real time data on the time, position and type of lightnings. These data can be displayed over a map background by indicating the position of each lightning, or as frequency maps.

With the front-analysis toolkit, different front lines, other linear objects, areas, and symbols can be drawn and edited.

The trajectory display makes it possible to visualize pre-calculated trajectories and to initiate the calculation of new, user defined trajectories. The actual trajectory calculations are not done by HAWK.

The transport module allows the user to display the results of pollution transport models.


Composite satelite image in the main window
Composite satelite image in the main window

Advanced visualization techniques

Advanced map visualization: The map display is the central component of the software, since it is by far the most common way to visualize meteorological data. The most important feature of the map display is that the projection of the data on the map is done upon loading the data. This way hawk does not require the data to be stored in the same lattice as it is displayed. Any field can be placed on any map area. Currently HAWK-2 can use the following projections:

Stereographic (the projection plane can be arbitrary, except equatorial). Most of the maps use this projection.

Mercator

Lambert azimuthal area-conserving

Equatorial azimuthal area-conserving

The number of map projections is not limited, for any projection type, any number of them may be defined for any part of Earth. It is also possible to use orographic relief background images.

VAD (Vertical Azimuth Display): Special display type for Doppler radars. Vertical profiles (wind, divergence, vertical velocity) are displayed on a time-height diagram.

 

Emagram: The results of radiosonde measurements can be displayed on emagrams. Using the measured values, HAWK-2 can calculate a number of stability parameters, and special quantities (CCL, TC, etc.). It is also possible to view forecasted profiles (currently ALADIN/LACE pseudotemps). The emagram display's unique features are the following:

It is possible to create a hodograph.

The software calculates various parameters (LCL, LFC, EQL, CAPE, CIN) by tracing a particle started from an interactively defined starting level, and colours the positive and negative areas on the emagram.

Spatial vertical cross section

Spatial vertical cross section: With the aid of spatial vertical cross sections, the user can easily study and analyse the spatial behaviour of various meteorological variables. To create a vertical cross section, the user can interactively draw the line, where the profile will be drawn, select the numerical model, and up to 4 meteorological parameters.

Meteogram

Meteogram display: A significant improvement was the introduction of the meteogram display. Now the user can display the time evolution of a quantity (observed or forecasted) at a fixed geographical location. The observed, and various forecasted values of a meteorological parameter can be displayed together, making verification easier. Measurements of automated weather stations, that make a measurement every minute, can also be displayed. The increasingly important probabilistic forecasts can be displayed as EPS plumes. Temporal cross sections are also part of the complex meteogram display.

Trajectory: The HAWK-2 meteorological workstation can display the results of trajectory calculations. Via the interactive trajectory tools, the user may even initiate new trajectory calculations, by specifying the starting location, and deciding which NWP model results the trajectory calculator should use. The trajectory display is useful in predicting the spread of an airborne pollutant.

Transport module: In predicting and following the spread of pollutants, the transport models that also take into account the changes of polluting materials (physical and chemical changes, radioactive decay), can supplement trajectory calculations. Transport model fields show the concentration and deposition of the pollutant over a map background.

Front analysis: An important step towards making HAWK-2 an advanced meteorological workstation instead of just a visualization tool, was to include an editable data type, the front-analysis. Frontlines, weather symbols and areas of various weather phenomena can be displayed and drawn. Front analysis can only be displayed over map backgrounds.



 

3D display: The 3D field display is available from within HAWK since 2004. The 3D display is able to visualize iso-surfaces of 3D numerical fields over any geographical area, selected by the user. The displayed objects can be interactively translated, rotated, and zoomed on the screen.

    3D display
3D display

The main steps of the development

The development of the HAWK system was started on the summer of 1994. The first operational version (HAWK-1), designed to simultaneously display various meteorological information (radar and satellite images, surface and upper-air observations, forecasts) was launched in January 1998. HAWK-2 that is in operation since the August of 2000, contained numerous upgrades, and major structural changes. The international (English) version of HAWK-2 was created in 2004. In 2005 a single, unified version of HAWK-2 was created and put to operational use.

Commercial value

Non-local users: As HAWK became a basic tool of the forecasters, it was necessary to make it available to our partners, who needed and worked with complex meteorological products. Currently HAWK is operational at the following Hungarian partners: OVF, MAVIR, HUNGAROCONTROL and BAHART.

International HAWK: In 2004, the Royal Meteorological Institute of Belgium chose HAWK-2 from a selection of other workstations, and purchased the English language version. To be able to comply with this request, a language module was added that is able to support a great number of languages (via the use of dictionary files), and makes further translations easier.

Projects related to HAWK

Product generating package: In 2003 an automated product generation package was created, based on the source code of HAWK-2. The PRODGEN package is a collection of tools, that can create images from the major data types in HAWK while running in the background, without the need to run an interactive session of HAWK. The PRODGEN tools can be executed from the command line; the options for creating the images are set via switches, command line arguments and parameter files.

Long term plans with the HAWK system

The HAWK-2 system has reached its maximum complexity by 2004. All the planned features of HAWK are implemented. New sources of conventional data types are constantly added.

However there are completely new data types, that do not fit well into the existing structure, and their implementation would require major structural changes. New programming tools and techniques offer significant improvements in flexibility, reliability and efficiency. Platforms, and computing power have also changed tremendously. These reasons persuaded us to create a new system, with a more flexible design, that would allow rapid incorporation of new data types, more efficient use, quick installation, and a more maintainable source code. The development of the next generation HAWK-3, has begun in 2004.