The most modern smartphone devices already have a GPS sensor built in. Why not using one device for on-road and off-road navigation?

Pros and Cons

Pros

• One device for everything: Car navigation, back country navigation, hiking, biking, taking photos, making videos
• Lightweight
• One battery charger only
• No extra paper maps, the digital maps are up-to-date
• Good Apps also show you point of interest near your actual location
• Routing possible, let the device calculate the best way to the destination
• Download tracks from Internet GPS communities directly on your device

Cons

• No backup if the only device fails
• Paper maps allow a better overview
• Battery capacity limited

The perfect smart phone for outdoor navigation

doesn't exist up to now :-)

Supposed it would exist:

• Large display for good map overview, at least 3.7 inch
• Good resolution, 900x500 pixel or better
• Bright display to be readable in direct sunlight >400cd/m²
• Good contrast
• Non-specular display
• Scratch-resistant display
• Shock resistant
• Strong battery to allow at least one day of back country navigation
• Changeable battery
• Lightweight
• Water-resistant
• Good photo and video camera
• GPS, GLONASS and Galileo support

GLONASS is the Russian satellite navigation system, Galileo the European one.

Being in deep forests, canyons or steep mountains, the number of visible satellites is reduced which results in imprecise positions. If your device supports several satellite systems in parallel, it results in a better position.

Outdoor navigation Apps

For every mobile device platform are various Apps for back country navigation available. Many of them are even free of charge. The perfect back country App has this features:

• Track the current trip
• Maps
  • Support on line and off line maps
    • On line maps: Your device is connected to the Internet, and loads the next area when needed
    • Off line maps: Pre-load the entire map at home and load it on the device. No Internet connection necessary
  • Multiple map support
• Load and display routes
• Show speed, elevation, position, moving direction, compass, destination to target
• Support way points
• Display points of interest around the actual position
• Overlays: Show trail difficulty or track labels
• Allow to export the track
• Track statistic like altitude difference or average speed
• Automatically reduce brightness and switch screen off after some time
• Allow routing

 Outdoor navigation maps

There are two different map types available:

• Vector Maps
  • The map data are a set of points, lines and attributes. The mobile device renders the map in real time in the moment you move or zoom the map.
  • Pros
    • Perfect render quality in highest zoom levels
    • Compact map size
    • You could adapt the map style to your personal needs with the help of style sheets
    • Off line routing possible, the device can calculate a route
  • Cons
    • Moderate map quality mostly without elevation lines and hill shading
    • Slow display speed, since the device has to render the map every time
    • Especially in overview mode with large areas rendering is very slow due to the number details to render
    • Off-line available only

• Raster Maps
  • The map consist of a set of images already rendered by a map server e.g. Google Maps or 4UMaps
  • Pros
    • High speed display, since the device just shows images
    • Brilliant and high quality render style with hill shading and elevation lines
    • On-line and off-line available
    • The render style cannot be modified on the device, but with overlay technology additional map details can be displayed by the App If used in online mode, the maps are always up to date and need only some megabyte of storage
  • Cons
    • Every zoom level needs an entire set of images, the map size is bigger
    • Only on-line routing possible, since a map is only a set of pictures
    • Routing is calculated by server, Internet connection necessary

For off-road navigation, you need a topographic map. Maps like Google Maps or Bing Maps are not suitable for outdoor navigation.

On-line vs. Off-line maps

There is a clear trend using on-line maps. Why?

• On-Line Maps
  • Pros
    • Good map servers like 4UMaps are updated weekly. Using on-line maps gives you always the latest maps
    • Using on-line maps results in the absolute lowest storage footprint on your device, there is only the part of the map on the device that you are currently using
  •  Cons
    • You need a reliable Internet connection in the field
    • You need some kind of volume contract for your Smart-phone

The perfect outdoor navigation map

Is a topographic map with this features:

• Contour lines to check the terrain slope or to see if a track goes upwards or downwards
• Contour lines with elevation indication
• Peaks, passes and signposts with name and elevation
• Springs, drinking water
• All highways, streets, ways, tracks and trails. The way type is displayed by colors and the line style
• Trail difficulty displayed like hiking SAC or mountain bike MTB scale
• Sea, lakes, rivers and creeks with elevation and name
•  Areas like cities, forest, fields, meadows are displayed by colors and symbols
• Shelters, restaurants, supermarkets
• Public transport like railway and bus stop
• A bright map style for good readability in the sunlight

The best topographic map for outdoor and back country activities is undoubted: 4UMaps.com  

Limited battery capacity is always a problem. If your device has a changeable battery: Good, but this results into a device restart. Some devices are equipped with batteries with more than 3000mAh, this should be enough for several days off road navigation.

Some tips to stretch battery life

• Display
• Reduce display brightens
• Switch off the screen if you don't need it
• Use a instant-on App like e.g. "No Lock" to enable the screen without unlocking the cell phone every time
• Turn off WiFi
• Turn off Blue-tooth
• Disable "Background Data": Many Apps like E-Mail or weather Apps are synchronizing in the background. This needs energy and transfer volume.
• If you have an external GPS device, switch off the internal GPS and use the external GPS device coupled with Blue tooth
• Use Airplane mode, especially if the next cell phone antenna is far away

Routing

Routing is the calculation of the optimal way between two points. The term optimal depends on the operation purpose, e.g. the shortest way for a hiker, the fastest way for a car, or the most beautiful way for a motor cycler or cyclist. The routing is either calculated on the device or app (offline) with the help of vector maps, or online with the help of a routing service.

Online services are for example OpenRouteService or MyRoundTrip for the traveling salesman problem.