THE USE OF A GPS-MAPPING
PROGRAM IN ORIENTATION AND MOBILITY
Guide Dogs NSW/ACT
Day Phone: 61 2 9412 9341
2 — 4 Thomas St
Day Phone: 61 2 9412 9347
paper critically examines the potential applications of GPS*-based mapping
programs in the field of orientation as related to persons with vision
impairment. The program selected for this examination is OziExplorer.
The functions of the program will be explored in two main areas. Firstly, how
it can be applied in aiding the instruction and teaching of orientation skills,
and secondly, how it can assist persons with vision impairment address
orientation challenges during travel.
aim of this research is to illustrate the potential applications, and/or
limitations, of mapping and moving map software, which is now readily available
in the consumer market. Such an investigation is warranted due to the
customizability of this relatively new software. Programs, such as OziExplorer, offer more extensive configuration options,
making it possible to tailor to more specific user needs. With increased
versatility, significant foreseeable advantages include the ability to
customize functions to different user skill levels, that is, from novice to
advance travelers, and the flexibility to accommodate varying technical abilities.
mapping and moving map software has traditionally been used for sailing,
boating, off- road driving, hiking and geocaching.
Only in the last ten years has OPS mapping software incorporated street and
road routing. These newer programs have the capacity to manipulate data,
incorporate different sources of maps, that is, paper as well as digital maps,
and these added features provide greater accuracy and make trip planning
GPS: Global Positioning System
The research presented here covers the preliminary phase of a larger multiphase project commenced in mid—2005 by Guide Dogs NSW/ACT in
which has been developed specifically to tailor to visually impaired travelers.
Phase I and II focus on research, Phase III and IV will undertake more
practical assessments. Phase III will involve preliminary trials of moving map
programs in two stages. Stage I will trial the programs in teaching orientation
skills, such as the development of cognitive mapping skills, understanding of
object—to—object spatial relationships, and the development of spatial updating
and environmental flow monitoring skills. Meanwhile, Stage II would trial the
capability of these programs in addressing orientation challenges during
travel. These challenges include maintaining orientation, identification of
landmarks and information points, and solving the problem of disorientation.
Orientation and Mobility instructors will be present in both Stages of Phase
111. Lastly, Phase IV involves the development of recommendations for modifying
and/or expanding capabilities of the software to suit the needs of blind and
visually impaired users.
features do moving map programs offer?
Moving map programs incorporate a myriad of applications with the potential to assist and enhance orientation for travelers who are blind or visually impaired. However, for the purposes of this paper, only the main (or generic) features of these programs have been identified.
moving map programs help teach orientation?
Features of moving map programs with the potential to aid the instruction and teaching of
orientation skills are identified in relation to the ability to assist the following:
(1) development of cognitive mapping skills;
(2) understanding of self—to—object and object—to—object spatial relationships; and
(3) development of spatial updating and environmental flow monitoring skills.
An aspect of good cognitive mapping skills is an understanding of environmental concepts. Mapping programs include proximity zone alarms. These zones, when entered, will sound an
alarm. The alarm can be set as a beeping sound or customized voice
recording. A feature of moving map software is the ability to manipulate these
zones into different shapes. For example, a zone could be arranged into the
shape of a rectangle and follow the perimeter of a building or it could follow
the curvy layout of a rose garden. The ability to manipulate these shapes
allows for a more accurate representation of the environment.
and object—to—object spatial relationships
Hill, Rieser, Hill, Hill, Halpin & Halpin (1993) undertook a study on how persons with visual impairments explore novel spaces. The study found that in the ‘distance estimation task’, the highest performing subjects used strategies that linked objects to reference points.
are used to mark any point of interest, for example, a traffic intersection or
bus stop. Moving map programs include ‘navigate to a waypoint’ feature. When
activated, this feature can tell the traveler which direction a waypoint is
(bearing), how far away it is (distance) and the approximate amount of time to
reach the waypoint ) ‘Estimated Time Enroute’ or ETE) based on current speed.
feature could assist O&M instructors teach the skill of linking objects to
reference points by accessing information on the location of different
waypoints and how distances between objects and reference points change during
updating and environmental flow monitoring skills
Learning these skills requires improving other skills, particularly memory and the use of other senses, such as hearing and touch. To do this, a traveler needs to focus an attaining cues given by the environment and little assistance from a GPS receiver is desirable.
Proximity waypoints offer a non—intrusive method of navigating. Proximity waypoints are always present and are only activated when a traveler enters a proximity waypoint. Therefore, proximity waypoints would be particularly useful for marking dangerous areas. This leaves the traveler free to move about without interference from the GPS receiver until that is, an unsafe area is entered.
advantage of proximity waypoints, and waypoints in general, is that they are
essentially a position on map. This position is made up of coordinates
(latitude and longitude), which means that another OPS user, who, for example,
may have passed a new construction site and recorded the coordinates of that
site, can send that information La another EPS user who can then enter it into
their receiver. The benefit of this is user’s ability to regularly update
information about the environment as it comes to hand.
Can moving map programs assist travelers address orientation challenges?
Program features with the capability to assist travelers address orientation challenges
are identified in relation to the following skills:
(1) maintaining orientation;
(2) identification of landmarks and information points; and
(3) solving the problem of disorientation.
Maintaining orientation is a matter of keeping track of environmental flow. As mentioned, the ability to mark proximity waypoints is a non-intrusive way of teaching environmental flow skills. However, novice travelers may require more assistance and, in this case, activating the ‘navigation’ feature would be helpful. When activated, this feature includes voice prompts that tell the traveler how far they are from a chosen waypoint. The voice prompts, for example, would sound as follows “30 meters”, “20 meters”, “10 meters”, “you have arrived”. The regularity of the voice prompts will depend on the speed ‘of travel.
Track Error (XTE) information may also assist travelers in maintaining
orientation. XTE is the deviation from the desired course line, that is, how
far off track you are currently traveling. XTE information combined with
bearing information (direction to waypoint) would be valuable in assisting a
traveler maintain orientation.
of landmarks and information points
The main benefit of using moving map programs to identify landmarks (and information points) is the ability to set ANY location as a landmark. When traveling without the aid
a of a GPS receiver, travelers must rely on environmental cues to identify landmarks. Sometimes these cues are ambiguous or intermittent (e.g. the smell of a bakery shop) or are easy to miss (e.g. a crack in the footpath).
ability to set waypoints with a five meter radius makes finding landmarks
easier and also frees—up some conscious mental effort, which can then be used
to focus on improving mobility skills, for example, cane technique.
of landmarks can be made even easier using routes. A ‘route’ is a collection of
waypoints linked together. When navigating to one waypoint, a traveler avails
him/herself to bearing, distance and STE information. However, when traveling
along a route, travelers have the option of ‘forward’ and ‘reverse’ navigation.
The 055 receiver will always prompt you to next waypoint in a route and will
only direct you Lo the following waypoint once the proceeding waypoint has been
the problem of disorientation
A traveler’s ability to solve the problem of disorientation depends largely on the number of reorientation strategies they have available to them. With more strategies available, the traveler can exercise (and practice) their hypothesis testing and decision making skills, by selecting an combing strategies.
map programs include several features that increase the number of reorientation
strategies for travelers. These features range from providing minimal
assistance to almost total navigation assistance. For minimal assistance, a
traveler could activate the compass and find out which direction they are
traveling. For more assistance, a traveler could opt to navigate to a waypoint
and access bearing, distance and STE information.
traveling along a route, a traveler could activate the ‘reverse navigation’
and get back to the previous waypoint located just before they became disoriented, in addition, all GES receivers include a ‘tracking’ feature. This is also referred to as a ‘snail trail’ or ‘breadcrumb trail’ and is automatically activated when the GFS receiver is turned on. If all other reorientation strategies fail, a traveler can activate the ‘trackback’ feature and navigate back to their original starting position.
Although there has been limited development in adapting moving map programs to he none accessible by blind and visually impaired users a preliminary analysis of this software has been undertaken in line with two tenets held by Guide Dogs NSW/ACT.
first tenet, exploring the potential of off—the—shelf technology, is based on
the reality that products available to the larger consumer are generally at the
cutting edge of technology. Guide Dogs NSW/ACT believe that a failure to
explore these off—the—shelf technologies may translate into missed
opportunities for improving the quality of life for people who are blind and
second tenet focuses on lifelong learning. Guide Dogs NSW/ACT is a staunch
supporter of technologies that can assist people to learn the skills that will
help them achieve greater independence. Therefore, the focus of investigating
the potential of CPS hardware and software is not to develop a dependence on
these technologies but rather to use them to enhance orientation and mobility
skills so that a visually impaired person may travel confidently with or
without these devices.
Hill, S. W., Rieser, J. J., Hill, M.—M., Hill, N., Haipin, J., & Halpin, P. (1993). How persons with visual impairments explore novel spaces: Strategies for good and poor performers. Journal of Visual Impairment & Blindness, 93(S), 295-301.