Mobiilse laserskaneerimise kõrguslik täpsus kinnise ja osaliselt avatud taevalaotuse korral
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Kuupäev
2019
Kättesaadav alates
12.09.2019
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Magistritöö eesmärgiks on hinnata mobiilse laserskaneerimise kõrguslikku täpsust
keerulises keskkonnas.
Andmed saadi 2018. aasta aprillis läbi viidud Kunda linna tänavate mõõdistuselt, milleks
kasutati mobiilse laserskaneerimise süsteemi. Samal ajal toimus ka RTK GNSS
mõõdistamine. Uurimistöö jaoks valiti kaks polügooni. Ühte polügooni piiravad kõrged
puud ning teist polügooni piiravad osaliselt kõrged puud. Mobiilse laserskaneerimise
süsteemi kõrgusliku täpsuse hindamiseks arvutati trajektoorid nelja arvutusskeemiga,
kasutades järgnevaid andmeid: Kunda GNSS püsijaam, mõõteala kõrvale paigaldatud
GNSS tugijaam, otseedastatud satelliidi efemeriidid ning lõplikud täpsed satelliidi orbiidi
efemeriidid. Kõrguslikku täpsust hinnati kahel polügooni kindelpunktil, mis vastavad
nivelleerimise 2. klassi täpsusele.
Uurimistöö tulemusel saadi esimese polügooni kõrguslikuks veaks 7 mm, kui kasutati
Kunda püsijaama andmeid nii otseedastatud kui ka täpsete efemeriididega. Teise
polügooni veaks saadi vastavalt 17 mm ja 19 mm. Mitteideaalses keskkonnas oleva
tugijaama ja otseedastatud efemeriididega saadi esimesel polügoonil veaks 103 mm ja
teisel 75 mm. Kui tugijaama andmetele lisati täpsed efemeriidid, oli esimese polügooni
kõrguslik viga 6 mm ja teisel 21 mm. Uurimistöö tulemustest saab järeldada, et mobiilse
laserskaneerimise süsteemiga on võimalik saada umbes 2 cm täpsus isegi keerulises
keskkonnas.
The aim of the Master’s Thesis is to assess the mobile laser scanning elevation data accuracy in complicated environment. The data in the current study was obtained in April 2018 when the streets of Kunda town were measured by using the mobile laser scanning system. At the same time was conducted the RTK GNSS survey. To accomplish the aim of the study, two polygons were chosen. One polygon is edged by tall trees and second polygon is partially edged by tall trees. For the elevation data accuracy assessment of mobile laser scanning system, four calculation schemes for trajectories were applied, using the following data: the GNSS reference station of Kunda, GNSS base station that was installed next to the measuring site, raw broadcast orbit ephemerides and final precise satellite orbit ephemerides. The elevation data was assessed on two known points that accord to levelling second class accuracy. As a result of the study, the error of the elevation data in the first polygon was 7 mm, when Kunda reference station data was used with raw broadcast and final ephemerides. Error in the second polygon was accordingly 17 mm and 19 mm. When in the calculations were used raw broadcast ephemerides and base station that was not in perfect environment, the error in the first polygon was 103 mm and in the second 75 mm. When the precise ephemerides were added to base station data, the error in the first polygon was 6 mm and in the second 21 mm. From the results of this study, it could be concluded that the mobile laser scanning system measures in 2 cm accuracy even in complicated environment.
The aim of the Master’s Thesis is to assess the mobile laser scanning elevation data accuracy in complicated environment. The data in the current study was obtained in April 2018 when the streets of Kunda town were measured by using the mobile laser scanning system. At the same time was conducted the RTK GNSS survey. To accomplish the aim of the study, two polygons were chosen. One polygon is edged by tall trees and second polygon is partially edged by tall trees. For the elevation data accuracy assessment of mobile laser scanning system, four calculation schemes for trajectories were applied, using the following data: the GNSS reference station of Kunda, GNSS base station that was installed next to the measuring site, raw broadcast orbit ephemerides and final precise satellite orbit ephemerides. The elevation data was assessed on two known points that accord to levelling second class accuracy. As a result of the study, the error of the elevation data in the first polygon was 7 mm, when Kunda reference station data was used with raw broadcast and final ephemerides. Error in the second polygon was accordingly 17 mm and 19 mm. When in the calculations were used raw broadcast ephemerides and base station that was not in perfect environment, the error in the first polygon was 103 mm and in the second 75 mm. When the precise ephemerides were added to base station data, the error in the first polygon was 6 mm and in the second 21 mm. From the results of this study, it could be concluded that the mobile laser scanning system measures in 2 cm accuracy even in complicated environment.
Kirjeldus
Magistritöö
Geodeesia ja maakorralduse õppekaval
Märksõnad
magistritööd, laserskaneerimine, punktipilved, dünaamiline skaneerimine