Digital Elevation Model DEM created by MATLAB
The first thing needed to create the maps in this account is the DEM. In case of skull hill it was not possible to download height data in sufficient quality (10 m grid) from the internet or to purchase it from the survey authorities. So I made my own DEM using MATLAB.
This was done by imposing a 10 m grid onto a 1:5000 contour line map. As the area was some 500 m square in size the grid had some 50 x 50 = 2500 nodes. This was printed on a sheet of paper. Using a pencil I manually noted the height at some 300 nodes where the surface relief changed rapidly. These 300 height values were entered into the computer which computed the needed 2500 height values using two dimensional interpolation. It is also feasible to decrease the grid width to 5 m so we get 100 x 100 = 10.000 nodes. This finer mesh will be used later.
This DEM is the base for all subsequent maps.
(C) Thorsten Straub www.metal-detecting.de 2006-2011.