Sökning: onr:"swepub:oai:DiVA.org:hig-44154" >
Challenges and Solu...
Challenges and Solutions for Establishing Precise Geodetic Control Networks: Introducing an Innovative Method
-
- Bagherbandi, Mohammad, Professor (författare)
- Högskolan i Gävle,Samhällsbyggnad
-
(creator_code:org_t)
- 2024
- 2024
- Engelska.
- Relaterad länk:
-
https://urn.kb.se/re...
Abstract
Ämnesord
Stäng
- Human-made infrastructure, such as dams, bridges, tunnels, and high towers, requires highly precise geodetic control networks and continuous monitoring to detect potential failure risks and plan civil engineering maintenance works. In classical 2D geodetic networks, reducing slope distances to horizontal ones is an important task for engineers. The common practice for this reduction involves using vertical angles and applying trigonometric rules. However, using vertical angles introduces systematic errors, primarily due to air refraction, deflections of the vertical (DOV), and the geometric effects of the reference surface, whether it is a sphere or an ellipsoid. Therefore, employing vertical angles in establishing geodetic control networks in 2D is challenging due to these systematic errors. To mitigate the refraction and DOV effects, reciprocal observations of vertical angles can be considered, especially if the elevation differences are small. In this study, we quantify these effects and propose an innovative solution to eliminate these systematic errors in small-scale geodetic networks. Specifically, we propose a new technique that does not rely on vertical angles for the reduction of distances, which is called the network-aided method. Thus, the geometric, physical, and refraction effects cancel out in this method. The results of this study hold significant importance for surveying guidelines. The main advantage of the proposed method is less fieldwork and, hence cost reduction since there is no need for different OFF-construction (reference) and ON-construction (monitoring) networks. Consequently, the number of network points will be less than in traditional networks. There is no need for reciprocal observations since vertical angles are not utilized, while the precision remains equal or even superior (in terms of quality factors i.e., higher redundancy numbers and smaller error ellipses).
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Samhällsbyggnadsteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Civil Engineering (hsv//eng)
Publikations- och innehållstyp
- pop (ämneskategori)
- kon (ämneskategori)