SVG for adaptive
visualisations in mobile situations
Department of Cartography
Technical University Munich
Arcisstr. 21, D-80333 München
tel: ++49 89 289-22836
fax: ++49 89 280-9573
GISs are moving away from a system for experts towards
a more widely used tool for answering spatial related questions. The dawn
of new technologies on the horizon, such as telecommunication, mobile Internet,
and handheld computing devices, offers new chances to the everyday use of
geoinformation. Especially Location Based Services – making use of the known
mobile device position – are able to provide more valuable information to
the user. However, these existing approaches to mobile visualisation of geoinformation
mostly have a commercial background and are rather technology centred. This
quite narrow view ignores many relevant problems and does not fully profit
from the new possibilities a mobile cartography could provide. One major
problem are the limited resources in a mobile environment, ranging from low
CPU and memory to small screens and low network bandwidth.
Hence, after a brief description of the characteristics of the mobile environment
and its building blocks, we will sketch a general conceptual framework for
geoinformation use in a mobile environment based on an adaptive approach,
since we consider too much interaction between user and device in mobile
situations to be a hindrance. Interaction should therefore be limited to
bare necessities and, if possible, be replaced by adaptation methods, though
interaction should always be enabled.
The focus of this paper will be on adaptive and dynamic generation of visualisations
for mobile users on the basis of vector data. By adaptive visualisation we
mean the personalisation of the presentation mode in correspondence to the
current user as well as the adoption to the device and the current context.
Methodologically the adaptation occurs on different levels: content, technology,
and presentation form. We will put emphasis on the adaptation of the presentation
form and demonstrate how to use SVG for delivering adapted content to mobile
Important technical and research questions are discussed such as the dynamic
generation of SVG files from database content, depending on user, context,
and constraints, as well as the derivation of SVG from geoinformation coded
in GML or other XML encoded information. SVG seems well suited for the goal
of presenting dynamic and adapted geoinformation content to mobile users,
since it offers a lot of useful features for this task. We try to highlight
the relevant portions of SVG and touch the ideas of the SVG Mobile specification.
To illustrate the rather theoretical concept, sketched in the first part,
we will present some small demo examples showing the possibilities using
user models and context models for generating different visualisations from
the same information source. This part will show the server side generation
of SVG documents depending on the current user category and context type
using solutions such as the OpenSVGMapserver.
The examples should also outline some possible adaptation methods in SVG.
Adaptations can be achieved by applying SVG filters, hierarchically structuring
SVG documents, and progressively rendering SVG files.