Finding Your Way with Maps and GPS - Running Android: Using Your Phone and Tablet for Work and Play - page 146

Topographic (topo) maps show terrain using contour lines, unlike street and road maps
which give no hint of the terrain. Topo maps have many uses aside from outdoor recreation,
including land use planning, construction, zoning, and surveying. The U.S. Geologic Sur-
vey is the primary source of topo maps in the U.S. The Ordnance Survey produces topo
maps for Great Britain, and other countries have similar mapping services. Commercial
maps are produced using government mapping data and other data sources to create spe-
cialized maps for recreating and many other uses. Formerly available only as expensive pa-
per maps, there are now many sources of free or low cost topo maps online and as mobile
apps.
Backcountry Navigator Pro
Available in a free trial version, Backcountry Navigator ( http://bit.ly/1a8DDNs ) can dis-
play topo and other specialized maps for many countries. Map selections can be down-
loaded to your device for use offline, an especially handy feature for backcountry use. To
download maps, go to the map and area of interest, then tap the Map Layers icon. Tap
Select Areas for download, then draw rectangles on the screen to select the areas to down-
load. You can select multiple areas. When finished, tap Download, and then from the pop-
up, Begin Download. You'll be shown how much space the downloaded maps will require,
and the amount of free space on the device. Tap Proceed to start the download.
Backcountry Navigator makes use of GPS for location and navigation, and you can create,
download, and upload waypoints and tracks.
Backcountry Navigator comes with CalTopo 1:24,000 topo maps of the U.S., which are
based on U.S. Geological Survey maps; OpenCycle map, which covers many countries
worldwide; USGS topo maps; and U.S. Forest Service topo maps.
If you upgrade to the Pro version, you can choose from a huge selection of paid maps, such
as Bureau of Land Management boundary maps showing private and public land, hunting
unit maps, lake contour maps, and trail maps.