Mapping Hacks

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Chapter 5, Mapping with Gadgets

#53 Visualize Your Tracks in Three Dimensions

HACK

Map3D to make use of them. Start by extracting the DEM from the TAR.GZ

archive using WinZip, or any archive utility of your choosing. The names of

the .DDF files inside will start with a four-digit number, like

8505. Make a

note of this as well.

Next, fetch the sdts2dem utility from http://www.cs.arizona.edu/topovista/

sdts2dem/ and simply run it from the DOS command line. You’ll see a series

of prompts as follows:

Enter first 4 charcters of the base SDTS file name: 8505

Enter base output file name (exclude any extension): o38122f7

Enter in the four-digit SDTS filename prefix, followed by the USGS quad-

rangle unit code prefixed by the letter

o. You should be able to copy this into

your Wissenbach DEM directory, which is defined under File

➝ DRG, DEM

Directories. Wissenbach Map3D should now be able to make use of your

new elevation models.

If you happen to have GDAL handy, the following gdal_

translate

command might work for you instead of having to

use sdts2dem:

gdal_translate -of USGSDEM 8505CATD.DDF x38122f7.dem

See “Convert Geospatial Data Between Different Formats”

[Hack #68] for more details.

Wissenbach has stated plans to extend the program to use elevation data

loaded from “Seamless Data Download from the USGS”

[Hack #67], which

would make this process a whole lot easier, so stay tuned.

Adding Elevation to a Tracklog ...