Določitev položaja cerkvenega zvonika v D96/TM z uporabo terestričnega laserskega skeniranja
| Autor: | Hren, Tine |
|---|---|
| Přispěvatelé: | Marjetič, Aleš |
| Jazyk: | slovinština |
| Rok vydání: | 2020 |
| Předmět: |
RANSAC algorithm
national coordinate system državni koordinatni sistem oblak točk georeferencing church belfry udc:528.7:726(497.4)(043.3) terestrično lasersko skeniranje geodetska mreža izravnava parametrov krogle geodetic network algoritem RANSAC terrestrial laser scanning sphere parameters adjustment cerkveni zvonik georeferenciranje point cloud |
| Popis: | Cerkveni zvoniki so v preteklosti, zaradi višje postavitve, predstavljali primerne orientacijske točke pri detajlni izmeri. Ob razvoju metod satelitske izmere in predvsem z uvedbo koordinatnega sistema D96/TM so počasi izgubili svoj pomen. Kljub temu, so za razliko od talnih trigonometričnih točk, večinoma ostali nedotaknjeni. Kot taki omogočajo določitev transformacijskih parametrov med starim in novim koordinatnim sistemom. Zato potrebujemo določitev njihovih položajev tudi v novem koordinatnem sistemu. Postopek določitve položaja cerkvenega zvonika z uporabo terestričnega laserskega skeniranja, smo opisali na primeru obeh zvonikov trnovske cerkve. Postopek vključuje določitev koordinat oslonilnih točk za georeferenciranje oblakov točk. Kar zahteva določitev geodetskega datuma s kombinacijo izmere GNSS in geometričnega nivelmana ter klasično izmero geodetske mreže z izravnavo proste mreže in uporabo postopka S-transformacije. Na podlagi georeferenciranih oblakov točk smo določili položaj trigonometrične točke zvonika z izravnavo parametrov krogle. Podatke smo filtrirali z uporabo algoritma RANSAC tako, da smo imeli v izravnavi res le točke, ki pripadajo krogli. Rezultate smo primerjali s položaji določenimi na podlagi klasične geodetske izmere. In the past, church belfries, due to their higher layout, often served as reference points in surveying. With the development of satellite based positioning methods and the establishment of the D96/TM coordinate system, they slowly lost their significance. Nevertheless, unlike ground trigonometric points, they have remained largely intact. As such, they enable transformation parameters determination between the old and the new coordinate system. Therefore, we need to determine their positions in the new coordinate system. We described the determination of the church belfries position using terrestrial laser scanning, on the example of both belfries of the Trnovo church. The process involves determining coordinates of the tie points for georeferencing the point clouds. This requires the determination of the geodetic datum by a combination of GNSS measurement and geometric levelling, and the classical geodetic survey of the geodetic network with free-network adjustment and further use of the S-transformation. Based on the georeferenced point clouds, we determined the position of the trigonometric point by sphere parameters adjustment. The data is filtered using the RANSAC algorithm so that we only have points that belong to the sphere in the adjustment process. The results were compared with the positions determined based on the classical geodetic survey. |
| Databáze: | OpenAIRE |
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