global mapper (pdf)
TRANSCRIPT
Global Mapper is a viewer capable of displaying the most popular GIS raster,
eleva on, and vector datasets, allowing users to easily view, edit and export their
data in mul ple formats.
www.library.carleton.ca/find/gis
Page 1
Global Mapper
LoadingaDEMintoGlobalMapper
Load a Digital Eleva on Model (DEM)
View the DEM in 3D
Create an eleva on profile graph
Export the DEM to a 3D mesh for use in AutoCAD
Generate contours from the DEM
Export the contours to .DWG or .SHP formats
When you first open Global Mapper, it will look like
Figure 1. Click on the first op on to “Open Your Own
Data Files”. In the file browser window that pops‐up,
navigate to the DEM file you wish to open.
Alterna vely, in a separate file directory window you
can navigate to your DEM file and click and drag it
into Global Mapper. The DEM should load as shown in
Figure 2. The legend on the le side shows the eleva‐
on colour ramp.
Important: Se ng the Projec on ensures proper
measurements
Click on ”Tools” then ”Configure” and ensure that the
correct projec on is set. The projec on used should
be UTM and correspond to the correct zone. To
determine the appropriate UTM zone, go to the index:
h p://www.library.carleton.ca/interac ve‐indexes
and double click on the “UTM_Index.kml” file to open
in Google Earth. The last 2 digits of each index
corresponds to the UTM zone.
Figure 1: the opening window of Global Mapper
Global Mapper supports viewing of many popular data formats, including: DEM, DGN, DXF, ECW, MrSID,
ESRI Shapefiles, E00, MapInfo MIF/MID, MapInfo TAB/MAP, SRTM, JPG, PNG, BIL, BSQ, BIP etc.
Figure 2: a loaded DEM showing the City of O awa
Control
Centre
Zoom
in/out Measure Pan Iden fy
Show 3D view 3D Eleva on Profile
Figure 3: The Main Tools on the Toolbar
Thishelpguidewillshowyouhowto:
Page 2
Global Mapper ViewingtheDEMin3D
When viewing files with an eleva on component, such as
DEMs or LiDAR, you can click on the “Show 3D View”
bu on (see Figure 3 on previous page). This will open an 3D
View window where you can pan, zoom, and rotate the
view using the by clicking on the tool icons shown here:
Figure 6 (below): the eleva on profile graph showing changing
eleva on over distance.
CreatinganElevationPro ileAn eleva on profile graph will show you the eleva on in a cross‐sec on of the DEM., as shown in Figure 6. To
start, click on the “3D Eleva on Profile” bu on (see figure 3 on previous page). This will pop‐up a “Tip” box,
to which you can just click “OK” to.
With the cursor, click to draw a line across the DEM for which you are interested in seeing the eleva on pro‐
file for (Figure 5). Le ‐clicking will stop drawing your line and the eleva on path profile window will pop‐up.
Figure 4 (le ): a 3D view of Ga neau Park from the O awa DEM.
ExportingaDEMtoa3D.DXFMeshforAutoCADA 3D surface model for use in AutoCAD can be created by expor ng the DEM into a DXF mesh. The first step is to
roughly zoom into the area you are interested in expor ng. Try not to take too much excess area, in order to speed up
the drawing process of the mesh.
Once you’re zoomed into your area, click on “File” then “Export Eleva on
grid Format”. This will pop‐up the “Select
Export Format” window (Figure 7). From the drop‐down menu, select the
“DXF
mesh” file format; then click “OK”.
Con nued on next page….. Figure 7 : the Select Export Format pop‐up window
Figure 5: the eleva on profile cross sec on line
Page 3
Global Mapper
Next, a “DXF Mesh Export Op ons” box will appear (Figure 8). You can change the pa‐
rameters to whatever suits your dataset, but remember to check ON the “Interpolate
to Fill in Small Gaps in the Data”.
Secondly, click on the “Export bounds” tab, then the “Draw a Box” bu on to more spe‐
cifically select your area to export by drawing a box in the pop‐up window. Everything
inside this box will be exported to your mesh.
Once you press Ok, a file browser window will pop‐up. Locate your output folder and
give the mesh an appropriate name. The expor ng will begin...this may take some me
depending on the size of your area.
ExportingaDEMtoa3D.DXFMeshforAutoCAD...continued
Figure 8 (le ): the DXF Mesh Export
Op ons (General) window.
Figure 9 (right): the DXF Mesh
Export Op ons (Export Bounds)
window.
Once your mesh is done
expor ng, open it in AutoCAD
Map 3D.
When it first opens, you will
only see black or a grey grid.
Click on the “3D” bu on to
view the mesh properly in 3D,
as seen in Figure 10.
Figure 10 (le ):
The 3D mesh
surface shown in
AutoCAD Map 3D Click on the “3D” bu on to ini ate this view.
Page 4
Global Mapper
Contours can be generated easily in Global Mapper by clicking on File, then Generate
Contours...This will open the Contour Genera on Op ons window, as shown in Figure
11. The main thing you have to fill out is the Contour Interval; however, you can cus‐
tomize some of the other op ons as you see fit. The smaller the contour intervals, the
longer it will take to generate.
Similarly, if you click on the Simplifica on tab, you will see a slider (Figure 12). To the
le creates smoother contours (i.e. less angular), but takes a bit more me.
To select the area you wish to generate the contours for, click on the Contour Bounds
tab and select the Draw a Box bu on. Press OK once you are done to start the contour
genera on.
GeneratingContours
Figure 11: the Contour Op ons window Figure 12: the Simplifica on tab
Figure 13: the newly
created contours.
To export theses
contours as vectors in
SHP or DWG formats,
select from the menu
File then Export Vector
Format…