Steps for Extracting from a DEM Elevation Data from Point Grid within an Irregular Polygon ?
I working on a geomorphic analysis the landforms of a part of Louisiana using Global Mapper 17 and the lidar DEMs from the Louisiana Atlas website.
What are the precise steps that can be used to create a point grid with regular rows and columns for an entire irregular polygon, which enclose a landform of interest and extract elevation grids from these point grids? I would like to do something similar to what what was done with slope, except with elevation, in the May 1, 2016 Blue Marble video, “Analyzing Terrain in Global Mapper,” starting at 1:02:00
I intend to use this elevation data for statistical analyzes, such as a frequency plot and calculation of the median value and interquartile range of elevations for each polygon. Can Global Mapper do such analyses? If not, what software is compatiable with data exported from Global Mapper?
An example of the type of analyses that the data will be used for is illustrated by:
Hassenruck-Gudipati, H.J., Ellis, T.S., Goudge, T.A. and Mohrig, D., 2021. A multi-proxy assessment of terrace formation in the lower Trinity River valley, Texas. Earth Surface Dynamics Discussions, pp.1-22.
An example of one of the irregular polygons that I am interested in extracting gridded elevation data from is selected in the below screen save from Global Mapper 17.
Any help that can be given would greatly appreciated.
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