TELEPHOTOGRAMMETRY: PROVIDING PHOTOGRAMMETRIC SERVICES FOR
MOBILE TELECOMMUNICATION USERS
Ch. J.-P. Blumer
Swiss Institute of Technology (EPFL), Photogrammetry laboratory, 1015 Lausanne, Switzerland —
Christian.blumer@epfl.ch
KEY WORDS: Photogrammetry, mobile mapping, multisensor system, GPS
ABSTRACT:
The purpose of this paper is to describe a research undertaken to develop a conceptual framework of telephotogrammetry based on
concepts such as telegeoprocessing, mobile photogrammetry, geomobility and web services. In order to be operational,
telephotogrammetry requires a combination of four different facilities: imaging, positioning, networking and computing. It consists of a
hand-held mobile mapping system ready to acquire, visualize and to transfer spatial information through the web. The system includes
also specialized servers communicating with the hand-held device and devoted to store the data and perform high intensive.
Based on a technological assessment, hardware component and software architecture were identified to fulfil the requirements for
telephotogrammetry. Preliminary results show that hardware components are not entirely suitable. In particular, network performance is
still a severe drawback for the transfer of information, i.e. image data. However software architecture is already available on the market
and provides good perspectives in term of human-machine interaction and task automation.
1. INTRODUCTION
1.1 Background
The continuous development of mobile telecommunication
systems provides large perspective in the field of ubiquitous
computing, where information can be distributed to a large
number of end-users anywhere at anytime. The ever increasing
miniaturization of devices is also a reality that helps develop
portable multi-sensor systems. Such a trend allows the
development of mobile services of various kinds and in particular
in the field of photogrammetry. In this context,
telephotogrammetry is a new concept that aims to widely
promote a range of services based on well-known
photogrammetric techniques to specialized and non-specialized
target users.
1.2 Motivations
The work about telephotogrammetry started with the idea to
combine three components: a camera, a positioning system and a
network interface on a hand-held device. Nowadays,
technological advances allow to find commercial on the shelf and
low-cost devices. Limitations in quality, precision and
performance have still to be assessed and software architecture
has to be developed in order to synchronize the functionalities of
the three devices and harmonize the interaction with the user.
Consequently telephotogrammetry was born so as to provide
remote image processing services to such enhanced hand-held
device.
There are several consequences of developing such a system.
First it allows a greater harmonisation between field and office
work as long as various users may access and process the same
data through a dedicated telephotogrammetry service. The
service is indeed distributed and may be accesses by several
users in the same time. Then, it also allows direct field validation
of processed data within some time delay, so as to reduce the
time for field operation. Finally, access to photogrammetric
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processing is given not only to trained users but also to a wide
public for specific applications.
1.3 Related work
The work involved here lays partly on the experience gained with
mobile mapping systems since its first advent in early 1980s
thanks to the public availability GPS signal. The current trend is
about mobile telecommunication and the development of remote-
driven applications supported on hand-held devices (Maguire,
2001; Grejner-Brezinska, 2004). Experiences are also carried out
with low-cost systems, where lack of precision is put up with
incorporation of external knowledge (Haala, 2003; Zlatanova,
2004). GPS receiver have gain tremendous advances by
providing more compact devices and more efficient data collector
(Wadhwani, 2001).
Another part of our work is strongly linked with the
developments in the fields of digital photogrammetry and close-
range photogrammetry. It is clear that more and more are these
technologies made available to a wider audience of non
specialized users (Fraser, 1997). Tools are simplified and already
implemented on common Personal Computers for even low-
accuracy applications. Also, digital photogrammetry is even
advancing towards automation (Heuvel, 2002).
The idea of making available photogrammetric processing
through telecommunication network was inspired by the initiative
called telegeoprocessing or telegeomatic (Laurini, 2001). This
initiative aims to provide GIS services the same way using
telecommunication systems. Web photogrammetry is already
nowadays a reality: ARPENTEUR is a good example of a web
based interface for photogrammetric processing (Grussenmeyer,
2001). Additionally, mobile photogrammetry has been mentioned
already in the literature (Fritsch, 2001), as a basis to develop e-
buisness. Various services, called Location Based Service
(LBS),.would be developed for mobile users, as for example a
Virtual 3D service.
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