GMDE Mobile
Note: GMDE Mobile has been discontinued and is no longer available. Please use the newer, and much better, GMDE Lite instead!
Most mobile device field mapping software is excellent for locating the geologist horizontally (in X and Y, longitude and latitude, etc.) but does not bring the third dimension, elevation (i.e., Z), into the picture. However, to do significant calculations that can aid the geologist while in the field, you need X, Y, and Z.
GMDE Mobile is one of the first mapping programs to allow the user to load a digital elevation model (DEM) for off-line use in the field.
See the Using GMDE in Teaching page for additional information.
This allows the geologist to do the following calculations:
Project a planar contact across topography, giving the mapper an immediate hypothesis to test in the field as well as improving mapping overall by plotting planar contacts exactly as they should cross topography. For example, in the above image, the four blue contacts were mapped with just 12 taps on the screen.
Calculate orientations from three-point problems, yielding strike and dips that reflect much more accurately the orientation at the map scale rather than the outcrop scale (of course, you can also enter outcrop scale orientations measured with a compass or with the iPad itself).
Calculate a planar orientation by best-fitting a plane to the vertices of a contact drawn on the map.
Determine map thickness of stratigraphic units just by tapping a point on the base and a point on the top of the unit.
Measure slope angle as well as distance.
To perform this magic, the user of GMDE Mobile will need to know or have access to the following skills:
Download GridFloat DEMs of the area in which they are interested. See additional notes later in this manual.
Produce base mapping materials (satellite images, topo maps, etc.) in mbtiles format as described later in this manual.
Upload these large digital files to the iPad that will be used in the field by connecting the iPad to a computer with iTunes software installed on it. Once connected, the user will use iTunes File Sharing to transfer the digital files to GMDE Mobile’s document folder.