Outdoor Navigation

Applications
Title	Outdoor Navigation
Author(s)	Rui Barradas Pereira.
Level	Basic
Year of Publication	2011

Outdoor Navigation consists in the navigation in outdoor environments such as natures trails. Outdoor Navigation is use mainly by outdoor enthusiasts (such as hikers, backpackers, geocaching enthusiasts, mountaineers or bikers) and outdoor workers (such emergency workers, wildlife preservation workers, forestry workers, farmers or mining workers).

Outdoor Navigation is somewhat different from Pedestrian Navigation or Road Navigation since it uses the concepts of trails and waypoints instead of a turn by turn navigation. Maps is not always required since individual trails can be loaded on the device or trails can be created from hikes. When present maps are very different from the maps used in Pedestrian Navigation or Road Navigation being more closely related with topographic charts and military charts instead of being street and road oriented.

Application Architecture

Outdoor Navigation is normally done using a custom Handheld Outdoor Receiver although standalone applications running on a mobile device can also be used. The Handheld Outdoor Receiver are prefered by heavy users since these devices are normally ruggedized devices to endure an outdoor environment. For the ocasional users there application than can run on GNSS-enabled phones with multimedia capabilities

Normally these applications work in a totally offline mode since it is normally that no celular coverage is not available in most of the site where Outdoor Navigation is used. Outdoor Navigation can be done without map support in the device although most devices support terrain maps with elevation information.

These applications have normally the following concepts:

• Waypoint: Point with coordinates. The user can mark waypoints in the device and can select the waypoint to go to.
• Track: List of sequential waypoints that lead the user from the initial waypoint to the last waypoint through the trail.
• Waypoint Navigation: The device leads the user through the trail by leading him from the last waypoint reached to the next on the trail.
• Track Log Recording: The trail taken by the user is stored in the device as a sucessive list of waypoints. This can be used to keep a record of the trail done that can be later downloaded or it can be used to return back in the trail.
• Return Back: The track log is reversed and the user is lead back to the starting point of the trail.
• Compass: These devices can be used as digital compasses. Some have a electronic compass that integrates with the GNSS positioning information.
• Altimeter: These devices can be used as digital altimeters. Some have a barometric altimeter that integrates with the GNSS positioning information.

These applications are considered non-critical applications although it can be used navigation on emergency situations.

The precision required by these applications is low. The current accuracy provided by civilian GPS enough although there might situation of heavy foliage cover and deep canyons where availability might less than what would be desirable.

Application Characterization

Outdoor Navigation was one of the first personal uses of GNSS and the first consumer handheld GNSS receivers were intended for outdoor use. Normally are waterproof or at least ruggedized and one of the design drivers of these devices is low power comsumption using regular bateries to endure continous use during long hours.

Geocaching is normally done using the same devices and applications used for generic Outdoor Navigation.

In technical term this is one of the most simple navigation uses of GNSS. The receiver simply points a straight line towards the next waypoint in the track that could have previously loaded or recorded by the user. No maps are required and the display can be a simple monocromatic screen to save batery.

Despite this there are Outdoor

as been wrongly seen as a mode of Road Navigation. But the fact is that the environments where pedestrians move around are generally more difficult than the road environment. Pedestrians normally move in sidewalks where the buildings shadow the GNSS signals, in tree shadowed environments and in indoor three-dimensional environments.

These environments are much more difficult than Road Navigation that even in urban environments will have better satellite visibility. To support indoor navigation these application would have to support inertial sensors integration or other indoor navigation techniques.

In simplified pedestrian applications the maps used for road navigation can be reused but this limits the degree of functionality that the application can provide. Pedestrians move in the sidewalks, not in the roads and can move more freely in the environment since they can use pedestrian streets or pathways and go across open areas.

The mapping of indoor environments is also much more complex and dynamic requiring three-dimensional mapping that is not generally required for road applications.

Also to support public transportation, the routes and the frequency or the timetable of the public transports must be supported making the database and the routing algorithms more complex.

Currently the interface for these applications is supported by the graphical and audio interfaces of mobile phone but these applications would benefit significantly from the used of augmented reality technologies.

Application Examples

Applications and services that fit in this category are:

• Journey Pro by Navitime: Journey is pedestrian navigation application for iPhone and Android.
• Ovi Maps: Nokia free navigation solution that supports pedestrian navigation in the Walk mode.
• Google Maps: Google free map solution that supports pedestrian navigation including public transportation.
• Personal Navigation Devices: Most road oriented personal navigations devices support pedestrian modes although usually the same maps and routing algorithms as for road navigation are used.