Browsing by Author "Kolodiy, P."

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    Assessment of qualitaty of quasigeoid models in Riga city
    (Видавництво Львівської політехніки, 2023-06-01) Celms, A.; Trevoho, I.; Kolodiy, P.; Pukite, V.; Virkavs, M.; Lidumnieks, T.; Latvia University of Life Sciences and Technologies; Lviv Polytechnic National University; Lviv National Environmental University; Latvian Geospatial Information Agency
    The study of the shape and size of the globe on a global scale is crucial to understanding the challenges and impacts of climate, the life sciences, hydrology, hydrography and geology on the planet as a whole. The Earth's topography – the surface, the relief topography that characterizes two different types of regions and certain local urban areas - is varied and changes occur periodically. The practical significance is to create a homogeneous geodetic reference system and geodetic frame based on certainty and reliability. A dynamic model of the globe could solve many future problems. Determining the topographic surface of the Earth - the altitude above sea level – using precise levelling methods is laborious task. Today, satellite-based measurement methods - GNSS - are used. GNSS allows to determine ellipsoidal heights using satellite systems and the global ellipsoidal model parameters (X,Y,Z). The geoid – surface of the mean sea level will enable to derive normal height from ellipsoidal heights; Then compared with the normal heights of the geometric levelling method. The need for a geoid or quasigeoid model in the economy is important for construction, navigation, logistics, users and maintainers of geographic information systems. A high-precision geoid or quasigeoid model would make a qualitative contribution to real-time GNSS measurements. The theoretical part of the study gives an overview of the shape and modelling of the globe; technological methods for the development of geoid and quasigeoid models; characteristics of geoid and quasigeoid models. The study includes GNSS measurements on known Class 1 leveling line points - obtaining ellipsoidal height values at 8 selected points in the southern part of Riga city. The obtained measurements were processed and the data were compared with available geoid and quasi-geoid models.
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    Posibilities of use of remote sensing technologies in the castle island measuring process in jelgava
    (Видавництво Львівської політехніки, 2020-01-22) Celms, A.; Reke, I.; Pukite, V.; Kolodiy, P.; Luksa, J.; Latvia University of Life Sciences and Technologies; Lviv National University of Agriculture in Dublany
    New technologies come into area of surveying more rapidly. By them work can be done safer, faster and in more interesting way and one of the newest technologies is laser scanning, result of which is point cloud, from which diverse three-dimensional models can be created. By combining photogrammetry and laser scanning methods, it is possible to obtain many-sided digital material of high quality, which is used for purposes of designing, project supervision, thus people's work is facilitated and made easier, in particular in places, which have difficult access or access can be life-threatening. The digital material, in this case relief model, allows performing above-mentioned activities remotely. For the achievement of the aim, following tasks were set: to study the available information on historical development of photogrammetry and laser scanning and principles of functioning of them; to research, analyse and describe strategy and program of sustainable development of Jelgava City; to analyse the situation of the planned Northern Flyover; to obtain spatial data for location of the planned Northern Flyover; to perform spatial data processing.