andyclift
Registered user
Anyone with a Montana should know about it's ability to take "overlay maps" i.e. scans of personal maps, sat images etc. which can be overlaid onto the existing maps on the Garmin.
I have used this to take screen shots or scans of OS 1:25000 maps in Memory Map and using these in the Garmin for walking routes. The way to match these maps to the ground using Google Earth works great when Google Earth shows roads and other distinctive features but is really hard to do when the Google sat image has no roads or other distinctive feature to position the overlay.
Now here is an easy solution.
Find three very clear features on the screen shot/overlay map that can be found in Basecamp or Memory Map, and using Memory Map or Basecamp make a direct triangular route between them. Now load that route into Google Earth and you have a clear triangle on the earth image joining three known points on the overly. Now when you load the overlay on the image and make it transparent it is very easy to line up the points on the overlay with the triangle.
I have used this to take screen shots or scans of OS 1:25000 maps in Memory Map and using these in the Garmin for walking routes. The way to match these maps to the ground using Google Earth works great when Google Earth shows roads and other distinctive features but is really hard to do when the Google sat image has no roads or other distinctive feature to position the overlay.
Now here is an easy solution.
Find three very clear features on the screen shot/overlay map that can be found in Basecamp or Memory Map, and using Memory Map or Basecamp make a direct triangular route between them. Now load that route into Google Earth and you have a clear triangle on the earth image joining three known points on the overly. Now when you load the overlay on the image and make it transparent it is very easy to line up the points on the overlay with the triangle.
