sigmet

sigmet − a Tcl package for viewing Sigmet raw product volumes in visky.

2.0

The sigmet package augments visky with the ability to draw Sigmet raw product volumes in maps.

When it loads, the sigmet package adds a Sigmet menu to the main menu bar with the following selections:

Load

This selection creates a dialog box that selects Sigmet raw product volumes to load into memory. The upper window lists directories. Double-click one to make it the current directory. The current directory is given as the window title. The lower window lists Sigmet raw product files in the current directory. Click a volume entry to select it. Click again to de-select it. Multiple selections are allowed. The Load button loads the current volume selections into memory, making them available for display. By default, the lower window shows raw product file name, volume time, Sigmet task that made the volume, and file size. When the current directory changes, the application scans all volumes in the directory for this information. During scanning, the Load button is replaced by a Faster button. Pressing this button during the directory scan reduces the information in the lower window to just file names, which is less informative, but more expeditious. There can be more than one load dialog, allowing simultaneous browsing of multiple directories.

Delete

This cascade menu orders deletion of volumes loaded with the Load dialog.

Data range

This cascade menu creates dialog boxes that set the data range for each Sigmet data type. Each dialog prompts for a minimum and maximum value for one data type. The application will use as many color levels as possible for the type. See Sigmet’s user documentation for information on the resolution of each type.

Saturation

The selection creates a slider that sets the saturation (gray-ness) of the sweep displays. Low saturation makes the sweeps look gray. High saturation makes them look more colorful. Use low saturation to improve visibility of items drawn on top of the Sigmet sweep.

The sigmet package also adds a Sigmet menu to each map. It will have a selection for each volume loaded. Each selection will lead to a cascading menu that selects the volume, sweep, and data type to show in the map. The None selection removes any sweep from the map.

The data display in the main menu shows values at the cursor coordinates for all displayed sweeps. There can be only one sweep in a map, although there can be several maps. See visky (n).

The button bar below the map provides convenient access to adjacent sweeps and volumes. The sweep buttons change the display to the previous and next sweeps in the current volume. The volume buttons change the display to the previous or next volume. The application will look for the next or previous volume in memory first - as denoted in the map’s Sigmet menu. If there is not one in memory, it will load the previous or next raw product file in the current directory, if available.

Shift-pressing a button has the effect of pressing it in all maps simultaneously. In other words, it shifts all maps to their respective previous or next sweeps or volumes, if possible.

The color legend and label can be dragged with the mouse. The color legend can be resized by dragging its lower right corner.

File parameter_directory/sigmet stores options and runtime information between sessions. See the visky (n) man page for more information on how the parameter directory is identified and used. parameter_directory/sigmet is a plain text file. It can be edited before loading the package to set defaults. The file is automatically updated with the current state when the package unloads, usually when the visky application exits.

Gordon Carrie <user0 at tkgeomap.org>