Using OS GeoTIFF data on Garmin Oregon

From Field of Cows

The OS GeoTIFF data is normally 4000x4000 pixels and is all in OSGB coordinate system. To get onto the garmin you need to create a Google kmz file which contains only jpg format images in WGS84 lat/long.

The best way to do this is by doing the following:

  1. Build a large GeoTIFF containing the area of interest.
  2. Convert to kmz
  3. Copy to device.

Build Large GeoTIFF

  1. Make sure you have the following packages installed in Linux:
  2. gdal-bin
    python-gdal
    
  3. Merge the GeoTIFFs with the following command:
  4. gdal_merge.py -of GTiff -pct -v -o output_file.tif in1.tif in2.tif in3.tif in4.tif
    

Convert to KMZ

There is a handy tool to do this on Windows called G-Raster. Find it here.

You can optionally resample to generate less tiles. Bear in mind that the Garmin at present will only support a maximum of 100 tiles. Resample if necessary to reduce tile count.

Copy to Device

  1. Connect the Garmin via USB
  2. Copy the KMZ file to \Garmin\CustomMaps. Best to do this on an SD card in case the map crashes the unit.
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