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ŠUMARSKI LIST 11-12/2010 str. 54     <-- 54 -->        PDF

P. Kovácsová, M. Antalová: PRECISION FORESTRY – DEFINITION AND TECHNOLOGIES Šumarski list br. 11–12, CXXXIV (2010), 603-611
2. SCOPE OF RESEARCH – Problematika istraživanja
The most important parts of precision forestry are
new and modern technologies.

Precision technologies are instrumentation, mechanization,
and information technologies that measure, record,
process analyze, manage, or actuate multi-source
data of high spatial or temporal resolution to enable information
based management practice or to support
scientific discovery (Schmoldt, Thomson 2001).

Precision forestry uses variety of tools and techniques,
which can be differently categorised. Ziesak classifies
techniques into seven main activity fields:

Surveying (terrestrial laser scanner, GPS, INS and
digital surveying equipment),

Remote sensing (CIR, Airborn laser scanner),

Contact-free materials testing and measuring computer
tomography (CT), ultrasound, video and laser

Monitoring - radio frequency identification (RFID)
and electronic nose (aroma) technology,

Decision-making and harvest planning,

GIS, DSS and visualisation software,

Computer hardware.
In this article tools are categorized into 5 categories.
2.1. Surveying technologies – Tehnologije izmjere
Currently, photogrammetric measurement methods
with support of terrestrial measurements using total
stations, electronic tachymeter and fieldmaper are dominating
in the forest mapping. However, these methods
do not provide information on all the details
hidden under crops, where there are various complications
caused by considerable segmentation and opacity
of terrain; that’s why geodetic (terrestrial) methods are
used for supporting of photogrammetric measurement

Forest mapping technology GNSS – They are
highly accurate satellite based radio navigation systems
which provide us three dimensional positioning (elevation
of the ground and coordinates x, y) and time information.
This system gathers data position single
objectives (Khali 2001).
GNSS users have now fully available two satellite
systems: NAVSTAR system developed by U.S.A and
the Russian GLONASS system. The third satellite system
GALILEO is the EU project, which aim is to build
a new and an advanced satellite system, which would
contribute to maximum efficiency in measurements of
GNSS. The successful launch and expansion of the GALILEO
system would be more than double the number
of GNSS signals, which will be available to users
(Tuček et al., 2007). Currently, in mapping both systems
are used, which increases the accuracy and availability
of mapping in extreme conditions (GLONASS
system significantly offset the deficiency of American
NAVSTAR satellites, which lead to increase of accuracy
and availability of GNSS technology in extreme
environments such as forest.

The equipment on the GNSS basis, sometimes called
GPS/GIS, is effective in data collection in forested
areas, e.g. also in forest stand description (forest taxation),
in forest detail object location and attribute collection
in forestry thematic mapping (Tuček et al.
2002). These systems are used mainly for navigation on

the ground and under canopy but LIDAR and IFSAR
remote sensing technologies are equipped with GPS for
obtaining accurate coordinate system of flying. At this
time there is an effort to equip the new forest (wheeled
skidder, track skidder) and agriculture technologies
with GPS because of its navigation and monitoring abilities.
GPS builds connections among map, image or digital
database and real, physical location on the Earth
surface. A possibility of usage of such equipment for
tracing and navigation (from the map, plan or image to
real conditions) is it’s another important attribute
(Tuček, Suchomel 2003).

Inertial navigation system – Inertial navigation
system uses gyros, which is able to maintain on long-
term indication of the specified direction. Measurement
is based on the spread of the laser pulse in very long
convoluted coils into fibreglass. With the progress of
the motion sensor there are also emerging inertial navigation
systems operating on different principles. These
systems consist of sets capable of very sensitive accelerometers
measurement changes in the direction of motion
sensor. This sensor works in conjunction with a
computer that continuously integrates the input signal
of the accelerometers and determines the current location
of the observed object. Inertial navigation is able to
measure even in densely forested terrain, where other
navigation may not work (Rapant 2002, Martinić
et al. 2001).
Terrestrial Laser scanner – Terrestrial laser scanning
systems allows obtaining a large amount of data
fast, called a point cloud. Point Cloud is a set of x, y, z
coordinates and sometimes number of intensity, which
after processing provides a 3D model of objects and terrain.
Current researches are focused on forest inventory
automation, for the derivation of forest stand and tree
characteristics (height, diameter, round base, number of
stem) and identification of the tree based on bark.