Järvselja puude kõrguse kõrgtäpne mõõtmine
Laen...
Kuupäev
2014
Kättesaadav alates
Autorid
Nõgene, Aigar
Zilmer, Kristjan
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Käesoleva bakalaureusetöö ajendiks oli SA Järvselja õppe- ja katsemetskonna poolt
tellitud projekt, mille käigus mõõdeti metskonna aladel olevate tähelepanuväärsete puude
kõrgused ja nende asukohad. Mõõtmiste teostamiseks kasutati kõrgtäpset
elektrontahhümeetrit Trimble S6 ja RTK GNSS seadet Trimble R4-2.
Teostatud töö eesmärgiks oli lähteülesandes märgitud 18 kõrge puu kõrguse määramine
ning selleks tarviliku mõõtmismetoodika väljatöötamine. Mõõtmismeetoditeks oli
vertikaalnurga ja kauguse ning elektrontahhümeetri laserkiirega mõõtmise meetod. Kohe
alguses sai selgeks, et laseriga mõõtmine on täpsem, kiirem ja otstarbekam.
Varasemalt on Järveljal mõõdetud puid Tallinna Tehnikaülikooli projekti raames
laserskanneriga 2013. aasta kevadel. Lisaks on sama aasta kevadel elektrontahhümeetriga
mõõtmisi teostanud ka Harli Jürgenson. Mõlema mainitud mõõtmise tulemused on
käesolevas töös ka välja toodud.
Andmete analüüsi käigus on kogutud tulemusi võrreldud varasema laserskanneerimise
tulemustega. Ilmnes, et üldjuhul jäävad puude kõrguste erinevused 0,5 m piiresse. Lisaks
on võrreldud puu kahte erinevat kõrgust. Esimeseks kõrguseks on jalami ja ladva vahel
arvutatud (lõplik kõrgus) ning teiseks ladva ja maapinnal oleva ladvaprojektsiooni vahel
leitud kõrgus. Nende kahe kõrguse erinevus jääb üldjuhul 10 cm piiresse. Suuremad
erinevused on tingitud puud ümbritsevast ebaühtlasest maapinnast. Kuna töös on
esialgselt kasutatud kahte mõõtmismeetodit, siis on nende tulemuste võrdlemisel
ilmnenud, et erinevus küündib isegi kuni 3,6 meetrini.
Kümne päevase välitöö tulemuseks on tähelepanu pälvinud 18 puu kõrgused, asukohad
ning maapinnale märgitud ladvaprojektsioonid. Iga puu kohta on ka asendiskeem, mis
iseloomustab puu, jaamapunktide, kasutatud tähiste ja ladvaprojektsiooni omavahelist
paiknemist. Puude koordineerimine L-Est97 koordinaatsüsteemis on võimalikele
tulevastele uuringutele abiks mõõdetud puude asukoha ja tähistatud ladvaprojektsioonide
leidmisel. Lisaks annab töö praktilise näite varal ettekujutuse kõrgete objektide
mõõdistustöö keerukusest metsas ning selleks kasutatava mõõtmismetoodika valikust.
The incentive of this bachelor’s thesis was a project ordered by Järvselja Training and Experimental Forest Center, whereby heights and the locations of remarkable trees in the area were measured. Measurements were performed using the high accurate Trimble S6 total station and RTK GNSS Trimble R4-2. The purpose of the work performed was to measure 18 high trees which were marked in the initial task and to develop the measurement methods to conduct the measuring. Measurement methods were vertical angle plus distance and with total stations laser beam. Quite early at the start it became clear that measuring with laser is more accurate, faster and therefore efficient. In the spring of 2013, the same 18 trees were measured with laser scanner during the Tallinn University of Technology project. In addition, at the same year, Harli Jürgenson made measurements of some of these trees with total station. The results of both mentioned works are brought up in the current thesis. During the data analysis, the results of this work have been compared with the results of laser scanning. It appeared that the differences between these two heights are generally within 0,5 m. Besides that, two different heights of these trees have been compared. The first height is calculated between the foot and the treetop (final height) and the second height between the treetop and the surface projection of the treetop. The difference of these two heights lies generally between 10 cm. The larger differences are contributed to the uneven ground around the tree. In comparison of the two measuring methods, it appeared that the difference reaches up to 3,6 metres. Ten days of fieldwork resulted in determing the heights, locations and surface projections to the indicated treetops of 18 trees. For every tree, there is a diagram of the position what describes the positions between the tree location, station points, used marks and the surface projections of the treetops. The coordinates in the L-Est97 coordinate system can be used in future studies because it is easy to locate the trees and the surface projections of the treetops. In additon to that, this work gives us the idea which measuring methods to use and how complex it is to conduct high objects measurements in the forest.
The incentive of this bachelor’s thesis was a project ordered by Järvselja Training and Experimental Forest Center, whereby heights and the locations of remarkable trees in the area were measured. Measurements were performed using the high accurate Trimble S6 total station and RTK GNSS Trimble R4-2. The purpose of the work performed was to measure 18 high trees which were marked in the initial task and to develop the measurement methods to conduct the measuring. Measurement methods were vertical angle plus distance and with total stations laser beam. Quite early at the start it became clear that measuring with laser is more accurate, faster and therefore efficient. In the spring of 2013, the same 18 trees were measured with laser scanner during the Tallinn University of Technology project. In addition, at the same year, Harli Jürgenson made measurements of some of these trees with total station. The results of both mentioned works are brought up in the current thesis. During the data analysis, the results of this work have been compared with the results of laser scanning. It appeared that the differences between these two heights are generally within 0,5 m. Besides that, two different heights of these trees have been compared. The first height is calculated between the foot and the treetop (final height) and the second height between the treetop and the surface projection of the treetop. The difference of these two heights lies generally between 10 cm. The larger differences are contributed to the uneven ground around the tree. In comparison of the two measuring methods, it appeared that the difference reaches up to 3,6 metres. Ten days of fieldwork resulted in determing the heights, locations and surface projections to the indicated treetops of 18 trees. For every tree, there is a diagram of the position what describes the positions between the tree location, station points, used marks and the surface projections of the treetops. The coordinates in the L-Est97 coordinate system can be used in future studies because it is easy to locate the trees and the surface projections of the treetops. In additon to that, this work gives us the idea which measuring methods to use and how complex it is to conduct high objects measurements in the forest.
Kirjeldus
Märksõnad
bakalaureusetööd