Global Mapper v25.0

Calculate Volume of Historic Wall

JannWendt
JannWendt Global Mapper User
edited May 2012 in Elevation Data
Hi,

maybe someone is able to give me a solution. The task is to calculate the volume of a historic wall based on a DEM with 1 m resolution. My Problem is that I don't know how I should define an appropriate baseline. The wall is heterogenous and the underlaying topography (base) has a changing height over the distance of the wall. If I specify a constant base height which is to low then too much volume is calculated and if it is to high not every part of the wall is included in the calculations.

Thanks for your help,
Jann

Comments

  • global_mapper
    global_mapper Administrator
    edited May 2012
    Jann,

    Is the wall a fixed height over the terrain or does it have a flat type over sea level and the height varies with the terrain? In either case you can create a terrain surface from the wall area using the Advanced Feature Creation option in the Digitizer Tool to Create/Flatten Terrain (make sure the box on whether the heights are relative to the ground is checked as appropriate), then use File->Combine Terrains to do a difference surface (signed) between the new wall terrain surface and the underlying ground. Then do a volume calculation from the original wall area on the new difference surface relative to fixed height of 0 to get the volume (the fill volume is the wall volume).

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    http://www.globalmapper.com