Frequently Asked Questions
I was working on my Prometheus project for over an hour, when I had a computer system crash. Is everything lost?
Probably not. There is an auto-save option within Prometheus. If the auto-save function was active, then a BAK file will have been produced. The auto-save function saves the project file periodically and creates a BAK file, which replicates the project file. Simply rename the BAK file to the standard filename structure with a .fgm extension. To check the status of auto-save; go to File > Application Settings/Options and activate the CWFGM Configuration Options dialog window. The auto-save function is active if a checkmark is visible in the auto-save function window. The user can activate the auto-save function and specify the number of minutes for which the save function will apply. By default, the auto-save is active and set to 10 minutes.
How do I share the information within my Prometheus project?
There are two basic approaches to share information. The first option is to share the FGM project file, which contains all project related information and user interactions. This file can be sent to other potential users. When the project is opened on a new computer, the project will be duplicated. The second option is to export individual files. There are five export options available including:
- Grid Data - To export Grid Data, go to Landscape > Export > Export Fuel Grid on the Main Menu. A dialog box will appear requesting the file location and filename. This function is useful when the grid layer has been modified with the Fuel Polygon Patch tool. By default, the export file will use the standard ArcView Grid ASCII format. You should also export the associated FBP fuel type lookup table.
- Vector Data - To export Vector Data, highlight the desired vector file in the Component View, go to Landscape > Export Vector Data on the Main Menu. A dialog box will appear requesting the file location and filename. This function is useful when you have added vector fuel breaks or fire ignitions polygons. By default, the export files are in ArcView/ArcMap Shapefile (*.shp) format. You also have the option to export vectors in Generate (*.gen), MapInfo (*.tab) or KML (*.kml) formats. Vector data can also be exported from the Component View. Highlight the desired vector file in the Component View, then right click and select Export Vector Data.
- Last Fire Perimeter - To export the Last Fire Perimeter, go to Simulation > Export Last Fire Perimeter. A dialog box will appear requesting the file location and filename. By default, the export file is in ArcView/ArcMap Shapefile (*.shp) format. You also have the option to export the fire perimeter in Generate (*.gen) or MapInfo (*.tab) or KML (*.kml) formats.
- Weather Streams - To export a Weather Stream, highlight the desired weather stream on the Component View, go to Model > Weather > Export Weather Stream on the Main Menu. A dialog box will appear requesting the file location and filename. This function is useful if you have modified the original weather file or created a new weather stream. By default, the export file will use the standard text format. You have the option of exporting a header line with column descriptions. Weather streams can also be exported from the Component View. Highlight the desired weather stream in the Component View, then right click and select Export Weather Stream.
- Statistics View - To export a Statistics View, activate the desired Statistics View by clicking the menu bar in the window, then go to Simulation > Export Staitstics View on the Main Menu. A dialog box will appear requesting the file location and filename. This function is useful for providing hourly information on individual scenarios. By default, the export file will use the standard text format. A header line with columns descriptions is automatically added to the first line of the output file.
I was able to simulate a large fire in Prometheus, but the simulation was very slow. What optimization techniques are available to speed up the simulation?
You can control the number of time steps and hence the number of vertices that are added by specifying the distance resolution in Advanced Scenario Parameters. Increasing the distance resolution will decrease the computation time but will compromise the ability of the model to capture all of the detail in the fuel type grid.
You can also change the perimeter resolution in Advanced Scenario Parameters. This is the maximum distance allowed between two vertices along the fire perimeter. Increasing the perimeter resolution results in fewer vertices being added along the fire perimeter.
I simulated an actual fire, which I know did not burn during the night-time period. How can I address this within Prometheus?
You can control the active burning period anytime throughout the day by either setting the burning period or by setting thresholds for temperature and relative humidity. This option essentially turns off fire growth simulations outside the specified burning period. Night time burning can therefore be turned off. You need to specify a starting and ending hour of your fire simulation. Temperature and relative humidity thresholds can also be set. If the actual hourly temperature is less than or equal to the specified temperature, or if the actual hourly RH is greater than or equal to the specified RH, then fire growth will be stopped. The burning period identifies when fire growth occurs, however, within that period the temperature and RH thresholds will override the burning period settings, and will be applied.
These settings can be modified in two locations. The first is in File > Application Settings and Options > Burning Period Settings. The burning period settings can also be modified in the Component View (select a scenario, right mouse click and select Edit Burning Period Settings).
Can I use multiple Map Views to view the fire simulations at different scales?
Yes, you can display several Map Views at the same time. These views can be displayed either for the same fire or for different fires. If the same fire is being displayed, then the views can be zoomed to different scales.
What is the difference between Prometheus defaults and application defaults?
Prometheus defaults are the base modeling settings, delivered with the original model (first time install). They represent a standard set of values. In most cases you can always go back to the Prometheus default settings. Application defaults are the standard settings that apply whenever a new project is opened. Prometheus and Application defaults are set under File > Application Settings and Options. You also have the option to modify these settings at the scenario level. For example, FBP Options are set as Application defaults but can be changed and modified in the Advanced Scenario Parameters option for individual scenarios.
Last Modified: March 16, 2011