WA8LMF Home Page | Main APRS Page | Main Precision Mapping 9 Page | Updated  20 April 2012  

Using Precision Mapping 9.0's "Save As.." Feature to Create Accurate Static Maps 


Many APRS programs including UIview, APRSplus, Win/MacAPRS and Xastir can use images of maps exported or screen-captured from mapping programs, or scanned from paper maps.    Normally, making these images "line up" correctly in a mapping program requires knowing the exact latitude & longitude of at least two points on the map. Usually these are the coordinates of the upper-left and lower-right corners of the map image. 

In the past, this was often a tedious, trial-and-error process that frequently required conversions from one way of expressing latitude & longitude to another.  For example, from degrees & decimal degrees (DD.dddddd) to degrees, minutes & decimal minutes (DD MM.mm), or to degrees, minutes and seconds (DD MM SS).  The required calculations are not difficult, but the probability of errors and typing mistakes increases with the number of conversions done, and can become tedious and time-consuming if you create a number of maps.

Undertow Software's Precision Mapping 9.0 is widely used by Uiview users to display fully-scrollable and zoomable dynamic of the U.S. and Canada.   Precision Mapping has now been updated to make exporting accurately-calibrated fixed (static) maps, for use either in UIview or in other programs, EXTREMELY simple.

From the "Help, About" pull-down in Precision Mapping 9.0, check the version number.   If it is or later, the program has this capability.  If the version number is lower, click the "Check For Updates" button to automatically download and install the newest version.

The key feature in Precision Mapping 9.0 that makes easy export possible that saved images of the current on-screen map can be set to place the exact latitude/longitude coordinates of any corner of the map in the corresponding corner of the saved image.  Even better, the latitude & longitude values can set to any format:  DD.dddddd , DD MM.mm, or DD MM SS . The saved images can be in .BMP, .PNG or .GIF format, as required by the receiving program.

Step by Step Procedure

  1. Start up the stand-alone Precison Mapping 9.0 program (not UIview!). Zoom and scroll the display to the desired area and magnification.  The saved map will be an exact copy of the onscreen map, at the same pixel dimensions and resolution as the current on-screen display. Assuming you maximize the Precision Mapping window, the resulting map image dimensions in pixels will be determined by the display resolution set in the Windows control panel.

    For example, a 1400 x 900 pixel W-XGA display will yield a larger and more detailed view of the chosen area than a 1024 x 768 XGA display.  Consider the intended use of the image, and the resolution of the machine that will be using it, before choosing a display resolution setting.   A map saved from a 1024x600 netbook display will appear as a severely under-sized image on a 1920x1080-pixel HDTV-format monitor.  Note that in UIview, a map image larger than the display  (i.e. pixel dimensions greater than the screen's) WILL NOT be downsized to fit.  Rather the UIview screen becomes a scrollable view port allowing you to see part of the image at one time.

  2. Pull down "File, Map Settings":

    You will get an extensive Configurations menu with numerous sub-menus. Precision Mapping offers a vast array of display options that alter the appearance of the displayed map. You can emphasize or de-emphasize roads, show all roads or only major ones, show more or fewer cities, show/hide raised relief coloration, etc.   Pull down "File, Map Settings" and experiment with the display options.  Since the map is going to have APRS symbols and legends placed on top of it, one needs to experiment with settings that reduce the detail and clutter a bit, to make the APRS information easily visible and legible. 

    NOTE:  Changes made in these menus are "sticky"; any changes will return in the next session.

  3. Choose "General Settings, Coordinates".  Depending on the coordinate format the receiving application uses for calibrating it's maps, choose the appropriate format.   The UIview calibration dialog uses APRS/GPS   "DD MM.mm"   format, with the latitude first.  The circled formats below are correct for UIview. Users in Canada may wish to switch the distance Units to Kilometers.

  4. Select "General Settings, Scalebar Position".  If the scale bar is desired, place it in the upper right or lower left corner, so it won't overlap with the coordinate values that will appear in the upper-left and lower-right corners.

  5. Select "Road Features, Visibility".  By default, Precision Mapping 9 suppresses ALL display of roads when you zoom out to continental dimensions (Scale bar showing more than 300 miles). If you want the Interstates and other major roads to show at continental dimensions, check the "Highways Visible at" box for "500 mi/inch".  For closer-in views, experiment with enabling or disabling the various classes of roads to yield a legible not-too-clutttered display.

    The option for "High Contrast Streets" will change Interstates and other limited access highways from a muted orange to a more prominent red. At closer-in views, they will appear as a thick red line with thin black borders.  It also changes city street display in close-in views from a pale lavender to a bold red. 

  6. Select "Administrative, Area Shading".  If you are going to overlay transparent filled colored shapes such as Weather Service warning zones, APRS range circles, etc on the final map, you may wish to turn off coloration of states and/or counties.  To reduce clutter, you may wish to force the display of state/province names to the two-letter abbreviations instead of the full name.  This is specially useful in the crowded U.S. North-East/New England area; the full names tend to overlap into adjacent states.

  7. Select "Administrative, Boundaries".  The default presentation is a dotted line with a wider highlighter around it.  Setting this to "Solid" line and no "Highlite" yields a thin black line that makes for far less cluttered-looking maps.

  8. Scroll down the left-side list to the very bottom and select "Layer Control, Image Layers".  If you want the 3D-looking shaded relief to show under the roads, check the "Show Shaded Relief" box.  By default, the relief only shows when zoomed out to larger areas.  You can force the relief to show at closer-in views by editing the "Visible Between" boxes.  There is not much point forcing the relief display below about 10 miles/inch.  The relief layer is a bit-map image that will appear blurry or severely pixilated at closer views.

    The intensity (saturation) of the colors in the relief view can be increased by changing the "Opacity" setting from the default "50%" to a higher value.  You may also want to turn off coloration of counties and states in "Boundaries" above to avoid having the relief tinted in various weird ways state-by-state.

  9. OK out of the configuration dialogs.  Select "File, Save, Options".  Check the upper-left and lower-right corners to imprint lat/long values at these locations. If you want the Scale Bar to appear in the exported map, check this option also.

    NOTE: You only need to make all these choices once. In the future, you will only need to zoom/scroll to select the map area to be saved, and immediately go to "File, Save" discussed below.  
  10. Finally, select "File, Save, Map to File".  Choose an image format, file name and target folder and click "Save".  Normally, the 256-color .GIF format will yield the smallest image files.   DO NOT use .JPG format. 

    JPEG is the WORST POSSIBLE FORMAT for saving non-continuous-tone solid color images like maps.  The .JPG format is designed for continuous-tone images (i.e. photographs), and achieves it's compression by detecting gradual changes in color and brightness between adjacent pixels; i.e. gradients. On images with abrupt jumps of color or brightness between adjacent pixels such as maps, scanned black & white text, circuit diagrams, etc, .JPG compression creates a blurry, fuzzy mess at the transitions, that make small-point-size text and thin lines illegible.  

  11. An alternative is to choose "File, Save, Map to Clipboard" if you want to paste the image directly into image-editing programs like IrfanView or PhotoShop for further enhancement or annotation before saving to a file.

  12. You're done!   The map is ready for use.

 for some examples of maps exported by this process


Installing the Map Image Into UIview

  1. Start UIview and the Windows File Explorer. Place the File Explorer on top, and resize it so that part of the UIview screen is visible underneath it.
  2. Using the File Explorer, locate the file saved above, and drag/drop it into the open UIview window. The map image will appear in UIview's main window, temporarily displacing whatever map was showing before.  This dialog will pop up above the new map. 

  3. Type the coordinates showing in the corner of the map image into the corresponding boxes of the dialog. Take care to note a) UIview's quirk of requiring TWO delimiting periods in the string, and b) that the N/S & E/W labels come AFTER the numeric string. 

  4. Scroll the map so the lower-right corner shows and repeat the process.

  5. Enter a free-form description of the map. This description will appear in UIview's "Map, Load A Map" dialog.

  6. This process creates a second file with the same base name as the map file , but with the extension .INF . The file is a simple ASCII text file containing only three lines. For the map above, it will would like:

    40.29.50N, 106.24.02W
    39.13.24N, 103.59.41W
    Greater Denver Area

  7.  Copy both the map file and the matching .INF file to the \MAPS folder located under the main UIview program folder.

  8. In UIview, pull down "Map, Refresh Map List". Then do "Map, Load A Map" to use the new map.