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There are 11 icons beneath the Menu Bar. Each icon represents a different data type or graphic type, except the last two which allow clearing and reset. Not all icons have been implemented yet. GARP allows you to freely combine data of different types (i.e. satellite & model data, or radar & obs data, etc.) within the constraints of GEMPAK. Notice that as you pass the mouse over the icons, a window appears to tell you what the data or graphic type is.

When loading multiple frames into a loop, you may interrupt the loading by clicking on the CLEAR or RESET icons.

• Radar and Satellite Data:
  
  Display of satellite and radar imagery as in NSAT.
  The default number of satellite images to load is hard coded into GARP. You can change the images to select by clicking on the file name with your mouse. To select a single image, click once. To select multiple images in sequence, click and hold the mouse button as you slide up or down the list. To select multiple images out of sequence, press the CTRL key and click on each image to load.

• Surface Observational Data:
  
  Surface data plotted in a standard surface chart. Surface METAR's, Synoptic Code Observations, and ship/buoy data are now supported. The standard METAR's are available from "Hourly/METAR", synoptic code reports from "synoptic", and ship and buoy from ship/buoy. You can select/deselect which data is plotted by clicking on the Station Layout button. The default uses one color for all data; the multi-color button activates multiple colors. All the available dates/times from the data files are listed in the scroll window. Select the date/times with the mouse.

• Profiler Data:
  
  Profiler data from individual sites can be plotted as a time series over some time interval, usually 24 hours.

• Upper Air Data:
  
  Plan View:
  Upper air observational data plotted in a standard upper air chart. You can select/deselect what data is plotted by clicking on the Station Layout button. You can change the level by clicking on the Pressure Level button. All the available dates/times from the data files are listed in the scroll window. Select the date/times with the mouse.

  Vertical View:
  The vertical view menu lets the user select between Skew-T and Stuve diagram respresentations for soundings. A station selection widget is provided in addition to the time widget. Stability indicies are calculated and plotted with the sounding.

• Gridded Data Plan View:
  
  Gridded data plotted with contours or vectors (barbs or arrows). GARP can display gridded data from a number of models, this is defined in the $GARPHOME/config/Garp_defaults file. There are five coordinate systems that grids can be displayed on.

  The level can be chosen by either pressing the Level button, or by typing in the level (or levels in the case of a layer quantity).

  The date/times/forecast hours listed in the scroll window are extracted from each data file. As a result, you may notice an extra second or two processing time.

  To get specific information about the available times, levels, and fields in a given grid file, press the Info button. This window will allow you to open a grid file and get a GDINFO summary of the available grids in the file.

  The "Scalar:" and "Vector:" buttons allow grouping of FDF's from which to choose. The scrolling windows contain some pre-defined functions for plotting gridded data. You may select any of these functions, and the GEMPAK GFUNC or GVECT specification will appear in the input window below the scroll windows. These functions are defined in "FDF"'s (Function Definition Files), which are text files stored in the $GARPHOME/fdf/ directory tree. Please see the section "Defining FDF's" below for more information about creating your own FDF's.

  In addition to the pre-defined functions, you may type in ANY valid GEMPAK GFUNC or GVECT in the input window. Inline parameters (^ @ %) are accepted. Please see "phelp gfunc" for more information. Note that if you are manually inputting a GFUNC or GVECT specification, you must select Scalar or Vector, as appropriate.

  For more user control over the way your contour/vector plot looks, click on the More button. This will allow you to specify contour lines or color fill; what type of line or list of colors to use; how often to label the contour lines; the contour interval, min, & max; whether H/L symbols are plotted; and for vectors whether wind barbs or arrows are used. Please note that the Field Description box may give valuable information on how a specific pre-defined function is used.

  Finally, in order to plot a gridded data graphic, you must be sure to select the date/time(s), the level, and a scalar or vector function. If you forget any of these your graphic will not plot. Some FDF's include the definition for the level. In these cases, any value in the Level box is ignored. Press the Display or the Display & Close button to draw the graphics. The Clear icon will interrupt the drawing.

• Cross Section Data:
  Much of the cross section dialog is the same as the plan view model grid display. The main difference is that you must specify the cross section end points in the form STN1>STN2 or LAT;LON1>LAT;LON2.

• Grid Time Height:
  The Time vs. Height Display is similar to the cross section display. The user selects a parameter to be displayed as a function of time at a single point. The point may be specified using a station identifier or a lat;lon pair.

• Vertical Profile Data:
  This option allows the user to plot a Skew-T or Stuve at any point within a grid domiain. This is useful for plotting the analysis profile at a location where sounding data is not available, or for viewing how the sounding profile will look at a given forecast time.

• Clear:
  Clear the window. This icon will clear the drawing window of all frames. You may also use the Clear icon to interrupt the loading of any loop. Note, the Clear button will NOT reset the graphics area (GAREA), so if you have zoomed or changed the default area, your graphic will stay that way.

• Reset:
  Reset the window and the graphics area. This icon will clear the drawing window of all frames and it will also reset the GAREA to the DEFAULT value. You may also use the Reset icon to interrupt the loading of any loop.

GEMPAK Online Tutorial > NPROGS > GARP

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