How to transfer layers to GPS Garmin

The portable GPS devices are very helpful during field work given their increasingly capabilities and new functions. Sometimes it is useful to navigate using our own generated geographic information in addition to maps which can be found in the GPS devices normally. This capability is especially useful when working in remote areas where general detailed cartography is not available or when you want to use your own-generated cartography.

In this tutorial I will briefly show you the basics of how to add our cartography to the Garmin GPSMAP 64 © and use it to navigate in the field. Using the free QGIS and an extra plugin which is also freely available.

Requirements:

• A kmz compatible GPS device (in this case I use the GPSMAP 64S ©).
• QGIS with Garmin Custom Map Plugin installed. (Open QGIS, click on Plugins > Manage and Install Plugins)

The basic point of this small tutorial is to take advantage of the capability of the GPS device to read .kmz files (which are georeferenced) and navigate using them as basemaps. In addition we will use the QGIS plugin: Garmin Custom Map which allows us to export our maps to fully compatible .kmz files.

First you need to create you map view in QGIS, adding and personalizing your layers as desired. In the next figure you can see a basic map, with three layers (roads in red, towns in green and rivers in blue) which I want to add to the basemaps in the GPS device which lately I would like to use to navigate in a remote area.

I manipulated these layers in order to obtain a clear reference and easily locate my points of interest. I added the roads which are not available with that level of detail in the GPS base maps and also the rivers which can be very useful when locating points of interest. You can add as much layers as you need, just be careful with the styles you choose since the screen of the device might not be optimal to correctly visualize your information.

Once your cartography is ready you can use the plugin and export your map as a kmz file, clicking the plugin button.

You will be requested to specify a name for the .kmz file and a destination folder.

It will create a .kmz file which finally needs to be uploaded to your device. This process is quite easy and only consists in copying the created .kmz file into the device’s Custom Maps folder. (Your GPS device needs to be connected as a storing device).

Then when you restart your device the new map will appear and you can enable it to be used when navigating as follows (Reference GPSMAP 64S).

Now you can choose the kmz from: GPS Menu > Setup Map > Select Map > Custom Maps

In the Setup map options you can enable/disable which maps do you want to see, in the last picture you can see that the map I created in the previous steps are now visualized in the GPS screen and now I can start navigating into it. And that’s it! You now can add costumed cartography to your GPS device and use it to improve your navigation experience.

Recommendations and tips:

• Raster layers can also be used in the map view and then exported to .kmz filed along with vectorial layers.
• Keep in mind the scale at which you want to work, for large areas maybe generate multiple tiles and enable them accordingly to your necessities is better than generating too large tiles.
• Keep in mind that the plugin exports uniquely which is visible in the map view of your QGIS application.
• This function is especially useful when navigating in remote areas, I used it to locate remote geological sampling points using a digitized geological map, with a roads map on top of it.
• This was only a example of adding maps to the default GPS’ maps and it is not the only source.

Written by: Marlon Calispa