Release notes - GRAL and GUI version 21.09

GRAL 21.09

  • The arithmetic accuracy of the prognostic flow field calculation has been improved
  • The memory consumption for prognostic calculations has been reduced, if not the entire domain area needs to be calculated prognostically
  • Output of a file “PrognosticSubDomainAreas.txt” showing the prognostic sub-domains areas
  • Optional reduction of prognostic sub-domains depending on the distance to sources (further reduction of memory consumption and faster calculation for large domain areas)
  • Optional deactivation of the online output (reduction of file accesses during the calculation)
  • Optional user defined scaling factor for the deposition velocity within vegetation areas
  • A slight overestimation (about 20 %) of the deposition was corrected
  • The generation of the vegetation mesh has been fixed
  • Several small performance optimizations
  • Compiled for .NET5 as single file application for Windows and Linux

GRAMM 21.09

  • Code clean up and performance improvements within the GRAMM radiation module
  • Removed the experimental dependencies of Windows-GDAL (introduced in GRAMM 20.01). GRAMM works in LINUX again
  • Removed the experimental Topography Index Algorithm (TPI)

 GUI 21.09

New features

  • Enable the creation of concentration time series for arbitrary raster cells as post processing based on the *.grz files (Menu bar “Analyze results” – “Generate time series for several evaluation points”)
  • Enable the creation of GRAL meteorological time series for arbitrary raster cells based on the *.gff files (Windfield analysis – Windrose button or menu bar “Windfield analysis” – “Wind statistics at a point”)
  • New features for the “Match-to-Observation” function including an automatic tuning option
  • Support for various wind rose sector widths in the wind rose view and new wind rose design. Im-proved quality of wind evaluations (Velocity Classes, Stability Classes,..) copied to the clipboard
  • Further improvement of the dual screen usability
  • Support for the new GRAL options (deactivation of GRAL online functions and the prognostic sub domain reduction, see Reduce the size of prognostic sub domains)
  • New option for displaying GRAL or GRAMM wind vectors in a relative height above terrain or at a height above sea (absolute height)
  • Item dialogs are no longer TopMost windows but child forms of the Domain window. This means that these dialogs do not lose their focus when the mouse pointer leaves the dialog. In addition, the dialog will be minimized with the domain window. Furthermore, the dialogs are clipped to the Do-main window. Each item dialog got an additional cancel button to avoid unintentional modifications. The question whether a new shape of a source should be applied is no longer asked for new sources, where no shape is available yet.
  • The usage of the unit kg/h as input for the emission rates of line sources in the user dialog has been enabled. The values are still saved in kg/h/km and converted within the dialog using the total length of the line source
  • Improved performance for the high percentile calculation
  • Further progress bars showing the real progress and additional cancel buttons for further long taking operations
  • New GUI settings option: enable or disable automatic scaling when loading or drawing vector maps.
  • GUI settings: it is possible either loading the entire wind file (default) or to discarding lines with wind speed 0 and wind direction 0 or shuffle the wind direction for lines with wind speed 0.
  • GUI settings: you can now select whether GRAL concentration files and GRAMM wind fields should be deleted or moved to the recycle bin when they are deleted. This option is enabled (move to the recycle bin) by default!
  • The GRAMM grid heights are displayed either for each cell (as used up to V 21.09) or per corner point (as used in GRAMM) using the new menu entry “View –> Show cell heights for -> “
  • Now you can write meteorological files *.met from the GUI. Therefore, for example, an imported *.akt or *.akterm file can be saved as a *.met file or an imported subset of a large *.met file (e.g. one ore more months or days) can be saved as new *.met file.


  • Fixed the reuse of shape objects (problem, when using shape files with multiple parts)
  • Fixed rounding errors in the wind rose visualization
  • Reset the new option for the conversion from kg/h to kg/h/km when selecting a new line source using the slider
  • Reset the cell heights view when creating a new GRAL domain area
  • Fixed a bug when a wall has only 2 edge points (such walls were ignored when reloading the project)
  • Correction of the cell index calculation (elimination of rounding errors from double to int)
  • Fixed invalid reset cancellation tokens (avoid NullReferenceException)
  • Fixed a bug in the GRAMM terrain mesh generation (one offset error); use a new terrain interpola-tion for the GRAMM terrain mesh, fix incorrect NoData handling
  • Disabled controls in the “Special Settings” dialog if a project is locked
  • Fixed a bug, if no item is selected in the most recent files dialog
  • Fixed the display of the adaptive roughness settings when loading a project
  • Further improvements for the Linux version
  • Fixed a rare error when reading the *.scl files or writing *.wnd files for the GRAMM export function
  • The unit of odor sources at the item info form (MOU/h instead of OU/h) has been fixed
  • Removed double cklicks when setting edge points
  • It is possible that an area source is not included in the file cadestre.dat if too large grids are set for area sources or the area sources are strongly divided. To avoid this problem, the raster size is de-creased during rasterization until at least two subareas are generated per area source.
  • Fix an incorrectly displayed sum emission in the deposition dialog
  • Enable all supported separator characters when showing the file emissions_timeseries.txt or when summing up the total emissions
  • A possible division by 0 has been fixed in the emission modulation preview window
  • Disable the selection of source groups for the receptor evaluation, because the evaluation delivers incorrect results when some source groups are not included

Detailed information can be found in the GRAL and GUI manuals.