Overlaying raster map on topo in Garmin Dakota

[Bob Guba]

When I send a raster map from GM to the Garmin Dakota it just retains the tracks that are on the map. Is it possible to overlay the raster map with the tracks shown with their individual track colors as in the case when I perform the lengthy process of overlaying the raster map in Google Earth and georeferencing it, saving it as a kmz file, and loading it in the Dakota CustomMaps folder?

[global_mapper]

Are the tracks rendering how you want them to in Global Mapper prior to export? I would expect the exported raster result to look just like what you see in Global Mapper.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[Bob Guba]

One correction. I discovered the track overlayed on the topo map in the Dakota 20 was not from the GM raster map I was working with but from a GPX file stored in the Dakota. Today I was successful in overlaying the manually referenced JPG file in GM over the topo map in the Dakota 20.

In Garmin Raster Export Options was I correct in checking Display on Top of Roads and Trails?
The overlayed map in the Dakota has a white collar added to it on the right and the bottom sides of the map that wasn't there as viewed in GM. Is this situation corrected in Export Bounds? If so why no UTM option? I use UTM all the time and rarely Lat/Lon and never MGRS.

[global_mapper]

You would only want to check the 'Display on Top of Roads and Trials' option if you want your custom map to be drawn on top of any road maps built-in to the Garmin unit, rather than under them.

The Garmin custom raster maps are defined to be lat/lon/WGS84 tiles. They do not support tiles in other projections, like UTM (understandably as the unit could slow to a crawl trying to reproject rasters on the fly). So if your data if not rectangular in lat/lon you will get a border to fill the JPG files out to a rectangle. There is not any way to mark that as transparent as JPG is the format that Garmin requires for the images and JPG doesn't support transparency.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[Bob Guba]

Thanks Mike. With your explanation I know now why the collars showed up on the overlayed map.

Bob Guba