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Previous: Looping GEMPAK Displays Next: GEMPAK Overlays: Multi-panel Displays Table of contents Frames User Manual GEMPAK Online Tutorial

16 GEMPAK Overlays
We've already seen a little of the overlaying capabilities of GEMPAK. When the CLEAR is set to YES, a new frame is created. With the XW device, loops were created using stored frames. When CLEAR is set to NO, graphics are drawn to the same frame which allows the creation of complex graphics with data overlays.

Tip:When CLEAR=NO, satellite and radar images are not dropped, since those images would obscure any graphics alrady drawn. However, the navigation information from the SAT or RAD projection is still accessed from those files, so that other data can be drawn on top of images already in place using the same projection.

Warning:YOU are responsible for ensuring that the times of the data you overlay make sense. GEMPAK makes no attempt to ensure that your 500mb map is for the same time as a GOES-8 image for instance.

Some Overlay Hints

  • To avoid the title line overwriting the previous title drawn, be sure to set the TITLE variable to a different line.

  • Be cautious of cluttering.

  • When using filled areas as overlays, a COLOR of 0 will prevent the filled area from blocking out graphics beneath for the value associated with that COLOR. In many cases you will want to use filled areas as the base image with other values plotted on top.

  • When plotting graphs, be sure to define the X and Y ranges, since the ranges of different parameters may be different. Also be weary of scaling changes.

    16.0  GEMPAK Overlays: Multi-panel Displays

     


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