Basic
steps of custom map creation for GPS personal navigation devices (PND)
Maps that come with personal
navigation devices usually cover cities, towns and highways only. The challenge
still remains on how to use a PND in lesser known areas, e.g. villages, hilly
or desert areas, forests or beaches. The maps that come with PNDs are usually
vector maps and require sufficient level of GIS expertise for their creation.
The issue of proprietary navigation software along with maps of proprietary
format also restricts ordinary enthusiasts from custom map creation for their
PNDs.
With advance of technology, the
availabilities of public domain maps, aerial photographs and satellite
imageries have made it easier to create custom maps with waypoints, routes,
tracks etc. for navigation in unknown areas. Image files of scanned paper maps
can also be used for navigation after geo referencing them with appropriate
software. During the interactive session, we discuss in detail about the
utilities available to create maps, how to automate the process of geo
referencing and how to use them in personal navigation devices (PND). We also
discuss on how to overcome the challenge of limited memory of a navigation
devices in handling image files of large areas. The use of public domain maps,
aerial photographs and satellite imageries are to be made in accordance with
the terms and conditions laid down in their respective web sites.
Waypoints, Routes
and Tracks
Before we get much
further into digital mapping, we should understand the three types of data that
personal navigation devices use apart from map image.
Waypoints are individual points, described by a set of north-south and
east-west coordinates. Waypoints are used to store the location of campsites,
rapids, portages, fishing spots and points of interest. For creation of
waypoints of an unknown area, one can turn to world wide web and there are
quite a few sites that will come out very useful.
Routes consist of a connected series of waypoints, describing a path
along a road, river or trail. We enter routes using a sequential set of
waypoints, and we can use that route to navigate as we travel.
Tracks are similar to routes, but rather than being entered by the
user, they are auto-generated by the GPS unit. The unit stores a waypoint at
regular intervals, building up a track that we can store. We can use this track
data to navigate along the path that we've saved.
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Waypoints
of Alipur Zoo, |
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By pressing a button, waypoints can be exported to and viewed in Google Earth |
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Use the
custom map in the PND with Oziexplorer CE preinstalled and locate your position. The map can be panned, zoomed
in and zoomed out in the PND. New way points, routes and tracks can be created
while using the map in the PND. |
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