No Disconnect

Well, this took long enough.

Broad Strokes

1. Data from the Shuttle Radar Topography Mission (best taken from CGIAR).
2. Use GDAL (gdal_translate) to convert to GMT’s .grd format.
3. Use GMT’s grdcut to cut out a region of interest.
4. Use GDAL (gdal_contour) to create a contour map, in ESRI Shapefile format.
5. Open GPSMapEdit, import said Shapefile, tweak environment parameters extensively. Save as Polish-format .mp file; export as Garmin .img file.
6. Use MapSetToolKit to install the .img file as a map that MapSource can see.
7. Use MapSource to send the file to the GPS.

Tricky Bits

• Steps 1 – 4 are pain-free.
• Step 2
  • File | Import | Shapefile. In the “From field” tab the labels must be clicked on, for some reason. Click. Click. Make sure the datum and coordinate system are correct.
  • Under File | Map Properties. Enter a unique 8-digit numeric key in “ID.” Give the map a name.
  • Tricky things to do under the “Levels” tab:
    • A “level” is a zoom level. Level0 is the most detailed; Level8 or so the least detailed. Map objects will only be visible at levels for which are not specified, or for levels that are not specified.
    • So, add as many levels, plus one, as you want your map to be visible in. The last level must be blank.
    • Moreover, in the “Bits” field of the “Level Settings” dialog box, starting from Level0, each successive level must use fewer bits than the one above it.
  • Close out the “Map Properties” dialog.
  • Select all of the contours. Right click. Modify | Extend All Elements up to Level — and enter in the number of levels minus 1. (The highest-level level must be empty.)
• Step 7. Described here.

Remaining Work

1. Figuring out what contour intervals are appropriate for which zoom levels.
2. Making it look better.

Credit/help/inspiration: here and here.