Global Mapper v25.0

Extracting elevation data from overlapping datasets

danbratton
danbratton Global Mapper User
edited September 2010 in Elevation Data
Hello,

I have two 45km x 45km datasets that have a 10 km overlap (so that the total size is 45 km x 80 km).

My concern is when I extract data from this overlap region. Which dataset will it use? Can I specify which one to use?

Thanks,

Dan

Comments

  • global_mapper
    global_mapper Administrator
    edited September 2010
    Dan,

    In the overlap area whichever data set is on top will be used. You can re-order them in the Control Center (layers on the bottom are drawn layer, so are higher priority) if you need to make sure a particular one is used.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • tjhb
    tjhb Global Mapper User Trusted User
    edited September 2010
    And if you want a blended transition in the overlap, then feather the upper* dataset along the adjacent edge by an appropriate number of pixels.

    (You can currently feather along the edge of the dataset, i.e. its bounding box, but not along the edge of its valid/visible pixels. If the best dataset is an odd shape, and has missing data on the same side as the overlap, then feathering may not be a good option.)

    *"Upper" means "lower" in the control centre.