Tools > DTM > Load DTM (select from Main Menu)
Load 'spotshot' file and build DTM.
A surveyed “spotshot” file covering the study area is required for the DTM routine. A typical file will have thousands of points, with a coordinate and elevation for each. The spotshots are normally done on a fixed grid of (say) 50m x 50m. The denser the grid, the more accurate the DTM.
The above function show an Open file dialog box to browse for and load in a spotshot file. The following data formats are supported:
*.xyz, *.yxz, *.txt (Text files with x,y,z coordinates in different sequences)
*.IdMesh (Binary Mesh files)
*.tot (ModelMaker TOT files)
•A typical *.yxz file is shown below:
Note spaces are used as deliminator.
•The following File Import Settings box will appear:
oNote the Number of header lines = 1 (i.e. the row containing Y X Z)
oData Format must be specified, viz. the Y X Z sequence.
oIf Commas between columns then the box must be ticked (the above example is space delimited, therefore leave box unticked)
oSouthern Hemisphere (negate X,Y) box must be ticked for southern hemisphere data. The above listed X and Y coordinate will be negated to comply with the southern hemisphere data coordinate system.
oScale X,Y,Z can be left unchanged at 1.00000. Only change this if coordinated must be scaled.
•The DTM is then built in memory. You can verify the extend of the DTM by selecting DTM > Show Points. The elevation of individual points comprising the DTM mesh can be checked by clicking on them and reading the Z value at the bottom right of the screen.