Openstreetmap for APRS

 

“Openstreetmap Client for APRS” is a modified version of Openstreetmap Client specific for use by APRS-Go.  Openstreetmap Client is developed by Michael Mayer, and his web site is http://www.mchme.com/cms. 

 

Installation Instructions:  Download OSM_for_APRSGo.msi and setup.exe to your PC.  Double click on setup.exe.

 

The APRS-Go version of Openstreetmap Client adds the ability to create an APRS Project - a set of map tiles that reside in a project file directory.  You create a project by the following steps:

 

  1. move the visible OSM map to the area you desire to download,
  2. zoom to a desired starting level,
  3. provide the name for the project,
  4. click on an area within the displayed OSM map,
  5. press a button, and five zoom levels of OSM tiles are downloaded into a directory named for your project. 

 

Add more areas to the project by repeating steps 4 and 5.  Copy the project directory to an SD card for use by APRS-Go. 

 

Why five levels?  Five levels of map tiles, starting with any selected tile, provide a compromise between level of detail and number of maps to download.  Each level that you drill-down into the map requires a download of four times as many tiles as the previous level.  Five map levels requires 341 tile downloads (i.e., 1 + 4 + 16 + 64 + 256 = 341). 

 

Some features of APRS Projects are worth mentioning.  The Openstreetmap Client settings, displayed in the Settings screen, do not apply to APRS Projects.  That is to say:

 

 

The APRS Project name, location and zoom level are stored.  APRS Project names are displayed in the “APRS Projects” dropdown menu.  Clicking on a project name will return you to the map position and zoom level displayed when you created that project. 

 

Turn APRS Mode On

 

To create or modify an APRS Project, you must first turn the APRS Mode on. 

 

 

Refer to Picture 1.

Picture 1.

 

Create an APRS Project:

 

Position the OSM map to the desired starting location for your project.  Note that zoom level is displayed in the upper right hand corner of the screen.  I prefer to start at the 9 zoom level.   This gives a good starting level, and provides an ending level of 13, which I find to be a good level of detail. 

 

Click the APRS Projects, Create New Project menu items.  Enter a name for your project into the space provided on the pop-up window, and click the OK button.  You now have an empty project.  The project directory for your new project is:

 

My Documents/osmmaps/mapnik/<Project Name>.

 

Select an APRS Project:

 

To use a project after it has been created, select it from the APRS Projects menu.  Verify that the name of the project is displayed next to the words “APRS Project:” near the top of the screen.  Make sure the correct project name is displayed.  See Picture 2.

 

Select an Area to Download:

 

Position the mouse cursor over the area of the map to be downloaded, and press the left mouse button.  This will highlight the underlying map tile.  If the map tile does not cover the entire desired area (and it probably won’t), you will need to repeat the download process for adjacent map tiles.   See Picture 2.

 

Start the Download:

 

Press the right mouse button and then left-click the “Add 5 Level Map” in the pop-up menu item.  The Download Start screen will be displayed.  See Picture 3.  Press the “Download” button. 

 

Picture 2.

 

 

 

Picture 3.

 

When the download has finished, another map area may be selected to download.  Press the “Download” button again.  When you are finished downloading maps, click the “X” at the top right corner of the “APRS Download” screen.

 

At times when the OSM server is slow you may receive a “Timeout” message while downloading.  You can press the “OK” button on the message screen, and then re-press the “Download” button to restart the download where it left off.  Or, you can return to the project at a later time to restart the download process, if the timeout condition persists.