Global Mapper v25.0

Sum GeoTIFF property over squares

Stephanie Saunier
Stephanie Saunier Global Mapper User
edited October 2011 in Technical Support
Dear sir or madam
I have a geo TIFF file (with a property, which looks in global mapper like an elevation) and a number of closed squares (on a different layer). I would like to sum the “elevation” of the TIFF file over the area of the square (and if possible to save it as an attribute of the square)
It is feasible? I looked in the help, but I did not find the answer!
Thanks in advance for your help
Stephanie

Comments

  • global_mapper
    global_mapper Administrator
    edited October 2011
    Stephanie,

    You can get close to that by selecting the area(s) with the Digitizer Tool, then right-clicking and selecting the option to calculate elevation stats for the area. Then you will have attributes with things like the average elevation, minimum elevation, and maximum elevation over the area. There isn't a sum of all of the sampled elevations, but I would think the average would be more useful.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Stephanie Saunier
    Stephanie Saunier Global Mapper User
    edited October 2011
    Dear Mike
    First, many thanks for your really fast answer which is greatly appreciated. (great support service!)
    I have a few more questions
    • Is there a way to save the average elevation as an attribute?
    • Is there a way to save the surface as an attribute ?
    • Is there a way to do it automatically over a large number of polygon?
    Thanks very much in advance
    Stephanie
  • global_mapper
    global_mapper Administrator
    edited October 2011
    Actually the Digitizer Tool option already adds all of the calculated values for an area as attributes of that area and also can be done on many polygons at once.

    I'm not sure what you mean by saving the surface as an attribute.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Stephanie Saunier
    Stephanie Saunier Global Mapper User
    edited October 2011
    Great this is exactly what I needed!

    For the Surface: Can the area of the polygon be saved as an attribute for the polygon ? (I know it is calculated but I have not managed to save it as attribute!)

    Thanks again
  • global_mapper
    global_mapper Administrator
    edited October 2011
    Yes, just right-click in the Digitizer and select to add feature measure attributes. You will then have an attribute with the enclosed area.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com