A new generation of the VISATT Mobile Mapping System has been developed in cooperation with Absolute
Mapping Solution (AMS) which truly delivers a mobile mapping platform that integrates multi-sensors subsystems
With the continued growth
of urban centers all
around the world, city
planners are required to
keep up with up-to-date geographical
at a faster rate. This has led to the
establishment of spatially-referenced
Geographic Information Systems (GIS)
for a variety of municipal applications.
This information, however, is
expensive to obtain by conventional
methods. In addition, conventional
methods supply only point solutions
and are therefore not suited to support
the increasingly complex requirements
posed by urban centers in a timely
fashion. Satellite remote sensing
and aerial photogrammetry are two
methods which can provide various
GIS information at high rates and
reasonable cost. However, with the
first method, the associated accuracy
is not suitable for many applications,
and in the second case the near
vertical field of view provides only
part of the information required.
Furthermore, the type and quality
of information required by the user
is changing, quite often the user
prefers a cartographically less perfect
product (e.g. map substitute) that
contains the most recent information
rather than a product of very high
cartographic standard but with outdated
information. Also, the demand for
user specific maps or data and for noncartographic
products such as reports,
images, graphs, and frequently asked
questions are steadily increasing.
For example; 3D digital maps (with
landmarks; road vectors; transportation
infrastructure information; etc.) that
offer more visual information to
make car navigation easier will soon
replace the conventional 2D maps.
3D digital maps with enhanced 3D
visualization will make maps even
more attractive, informative and attractive, informative and
interesting, supporting a new range of
Internet and consumer applications.
With the advances in satellite and
inertial georeferencing techniques
and the readily available of digital
imaging sensors, a considerable portion
of GIS information can be acquired
from moving vehicles. The advantage
of kinematic-mode data collection
is that the survey can be performed
much faster and therefore more
economically, whilst gathering mapped
data from a new dimension - in the
same plane where the data is seen and
needed, or what the human eye sees.
Mobile Mapping - The
venue for 3D Mapping
The concept of mobile mapping
or mapping from moving vehicles
has been around for as long as
photogrammetry has been practiced.
Early incarnations of Mobile Mapping
Systems (MMS) were however,
restricted to applications that permitted
the determination of the mapped
from existing ground control points.
Fifteen years ago, advances in satellite
and inertial location technologies
made it possible to develop mobile
mapping system differently. Instead
of using ground control as reference
for orientating the images, the
trajectory and attitude of the imaging
platform could now be determined
directly. This made mobile mapping
to be independent of preset ground
control points. Hand in hand with this
development was the change from
analog to digital imaging- a change
that has considerably evolved over the
past years (Schwarz and El-Sheimy,
2004). As a result, mobile mapping
systems have evolved from a concept
of academic interest to a commercially
viable industry and are currently at industry and are currently at
a point where they match classical
survey techniques in accuracy but
far surpass in economy, speed and
efficiency. These systems integrate
navigation sensors and imaging sensors
to determine the positions of the
imaged points.. Although, the idea of
mobile mapping is based on a simple
concept, the real world implementation
brings a lot of challenging problems.
These are a product of integrating
the concepts of kinematic geodesy,
navigation, remote sensing, machine
vision, and digital photogrammetry
sciences which have been always
treated separately. For more details,
the reader is advised to read the
article by Skaloud (1999) on mobile
mapping implementation problems.
The initial trials to build a Mobile
mapping system was a van for
highway inventory (HI) 1983 by the
University of Calgary (Schwarz et. al.
1993), however real implementation
of practical systems were developed
by the Centre for Mapping at the
Ohio State University and the
University of Calgary in the mid
nineties. The University of Calgary
system development objective was
"A mobile mapping system that
positions all visible objects of interest
for an urban GIS with an RMS
accuracy of 0.3 m while moving
through a road corridor at a speed of
60 km/h and a maximum distance
to the desired objects of 50 m. Data
acquisition must be automatic and
should contain real-time quality control
features. Data processing, except for
quality control, will be done in post
mission and should have separate
modules for georeferencing, image
data base management, imaging, and
quality assessment." (El-Sheimy, 1996)
The outcome of this project was the
VISATT Van. The VISATT system
- in its initial form - was notable
because of the large number of
imaging sensors it employed. Where
previous land-based MMS were simple
stereovision systems employing only
two forward facing cameras, VISAT
had eight cameras - permitting more
flexible data collection and better
imaging geometry. A new generation of
the VISATT Mobile Mapping System
has been developed in cooperation
with Absolute Mapping Solution
(AMS) which truly delivers a mobile
mapping platform that integrates multisensors
subsystems (See Figure 1).
In this article, an overview of the
VISATT van is given. The sensors
on board the VISATT are described
highlighting their system functionality
while providing an overview of the
system's operational mapping cycle.
System deliverables and accuracy
are discussed. Finally, an outlook
into the future development of the
VISATT including hardware, software,
and applications is presented.