The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Voi. XXXVII. Part B5. Beijing 2008
In 1979, an aeroplane, a UAV platform with fixed wings was
firstly used for photogrammetry by Wester-Ebbinghaus (1980).
But it was found that it is hard for the platform to approach a
target. Hence, helicopters, UAV platforms with rotating wings,
have been utilized for taking the close images of a target
(Wester-Ebbinghaus, 1980).
Zischinsky, et. al. (2000) utilized a helicopter to acquire 82
ground pictures and 38 aerial pictures acquired and created 3D
building modelings. Nagai (2004) generated a DSM from the
data acquired by a laser Scanner and a CCD camera mounted
on a Subaru helicopter whose maximum payload weight was
100kg. Jang (2004) used a mini UAV-helicopter to take the
images of ancient historic scenes. Wang (2004) developed mini
aeroplane to extract 3D building model from 2D GIS data and
one image. Everaerts (2004) designed a UAV-system which
was called pegasus. This UAV-system was equipped with solar
cells to fly longer time.
Most systems developed from these previous studies did not
have real-time (or rapid) mapping capability, which can
produce spatial information such as DSM and orthoimages of
the target area under an emergent situation. For the realization
of this capability, the raw sensory data acquired by a UAV
based multi-sensor system should be transmitted to a ground
station and automatically processed. These functions were not
fully integrated into the most of previous systems.
In the meantime, the individual technologies required for the
realization of the UAV based rapid mapping system have been
rapidly advanced in different fields. For examples, many robust
automatic processing algorithms have been developed for the
generation of spatial information from sensory data such as
aerial images and airborne LIDAR data in the photogrammetry,
remote sensing, and computer vision fields. In addition, based
on the advances in the fields of aviation and navigation, small
helicopters with a self-flying capability at a close range have
emerged. In summary, many individual technologies in the
fields of geo-spatial information, aerospace engineering and
electronics have been enough matured to be used for the
implementation of real-time rapid mapping system.
To realize the real-time rapid mapping for the practical uses in
many emergent situations, we plan to develop a light, flexible
and low-priced mapping system using a small unmanned
helicopter. As distinct from the existing UAV-systems based
expensive hardware, our system will be based on highly
sophisticated software instead of using a high-priced platform
and sensors. As being in an initial stage of developing this
system, we will present an overview of this project, including
the preliminary design, work breakdown structures, expected
product and others.
2. PROJECT OVERVIEW
2.1 Goals
The goal of this project is to develop a light and flexible system
to perform rapid mapping for emergency responses. This
system consists of two main parts, aerial part and ground part.
The aerial part is composed of a UAV platform, sensors, and
sensor supporting modules. The mounted sensors are GPS, IMU,
digital camera and laser scanner. The sensor supporting
modules undertake to integrate the sensors, transmit the sensory
data to the ground, and stabilize sensors’ attitudes. The ground
part is composed of three sub-systems with appropriate
software, which are a control/receiving/archiving sub-system, a
data geo-referencing sub-system, and a spatial information
extraction sub-system. The whole system is illustrated in Figure
2.
Figure 2. Introduction to real-time aerial mapping system
The sensory data acquired from the aerial system are images,
returned laser information, position and attitude of the platform
tagged with GPS time. These data will be transmitted to the
ground system through the sensor supporting modules. Then,
images and laser points autonomously will be geo-referenced
by the geo-referencing sub-system of the ground system.
Finally, from the geo-referenced sensory data, the spatial
information extraction sub-system autonomously will generate
DSM/DEMs and orthoimages of the target areas where disaster
or accident occurs.
2.2 Configuration
This project is one of a series of projects supported through
Korean Land Spatialization Group (KLSG) funded by Korean
government. The overall budget is about 6 million US dollars
and the period is about four years.
This project is divided into 5 sub-projects, as listed in Figure 3.
We are concentrating on the first sub-project, design of real
time aerial monitoring system for the first period (2007.11.30 ~
2008.8.30). Five sub-projects are grouped by research items
into three sectors, aerial sector, ground sector, system
verification as shown in Figure 4.
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for Real-time Transmission of Sensor Data
evelopment of Image Acquisition Stabilization System
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Figure 3. List of sub-projects