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           **              VIEW_MAP               ** 
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VIEWMAP is a companion program to GPS_LOG. It is used to view and
preview maps generated on a text editor as well as binary image files
saved by the GPS_LOG.


As the program starts it offers you a screen that lists *.MAP and
*.MXP files which you can display. The files are sorted, and you can
get up to 20 files per selection page. You navigate on the page by
pressing the arrow keys. Once you reached a file you want, press
enter. If you want a next page - press "N", press "B" to go back to
the beginning. Press "Esc" to cancel and exit the programme. The
program actually lists all *.M?P files (? can be any character), but
files with other extensions are probably not useful. You can rename
files by using the Alt-R key. 

Once you select the file you get a graphic screen with the map. If 
the map is binary (*.MXP) it is only possible to view the displayed 
data. With  (*.MAP files), you can move the map around by pressing 
the arrow keys and enlarge/contract the image by pressing Alt-+ or 
Alt-* keys.	The instructions for this and other functions are 
displayed on the left side of the map. To select another file
press any key (except one of the hot keys) to end up in the initial 
screen.

You can change the factor by which the map is rescaled by pressing
Alt-R, and the sensitivity of the arrow keys by pressing Alt-F. After
you input the appropriate values you come back to the displayed map.
The values you enter are saved to the VIEW_MAP.INI file and are used 
the next time you start the program.

While using GPS_LOG it is possible to save track data from your 
flight. Using VIEW_MAP you can redisplay the track by pressing Alt-T
and supplying the program with the file name.  The data logged to file
are overlaid on the map. The density of the plotted points depends on
how often you saved the GPS information to file, but there is a
minimum distance of x (in the range of 1 to 5 pixels) between points.
You set the x value in the VIEW_MAP.INI file. If you log data
infrequently, the track may be barely visible. You can use the Alt-D
key to change the track dot size. This setting is saved to the
VIEW_MAP.INI file.

You can save current map image to a file using Alt-S key. This is 
useful for saving binary images of tracks overlayed on a map for
later quick recall.	Binary maps are stored with the MXP extension.

The VIEW_MAP.INI file contains one more parameter in addition to the
two mentioned above. The display factor parameter  should be set by
editing the file in order to control the distortion of the image by
various displays. For the HP100LX computer display the factor should
be 1. For a standard PC screen the factor should be around 2. You
need to determine what is the appropriate factor for your monitor.
The best way to do that is to display a map containing circles, and
to check their elliptical distortion.

