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Map referencing tutorial 1 : How it works

Imagine that we have just four maps available and that this (map1) is the smallest scale / largest coverage:-

The three boxes illustrate the positions and coverage of the other three maps.

  1. At position (1) we can neither zoom in or out.
  2. At position (2) we can zoom in to map2 and back out to map1.
  3. At position (3) we can zoom in to map2, zoom again into map3 and then out through map2 back to map1.
  4. At position (4) we can zoom in to map2, zoom again into map4 and then out through map2 back to map1

Now consider a journey with the GPS running from point (1) to point (3) to point (4). Suppose we have set the option 'Jump to Max Resolution' on :-

As we progressed on our journey we would start on map1, switch to map3 at the edge of map2/map3, briefly switch on to map2 when we ran off the edge of map3, then finally end up on map4 near the end of our trip.

Last Updated 23 July 1999

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