Projects / Programmes
Assessment of the cadastral boundary stones marking for photogrammetric data acquisition using unmanned aerial vehicles, and the analysis of their effect on the positional accuracy of the point clouds and orthophoto
| Code |
Science |
Field |
Subfield |
| 2.17.00 |
Engineering sciences and technologies |
Geodesy |
|
| Code |
Science |
Field |
| P515 |
Natural sciences and mathematics |
Geodesy |
| Code |
Science |
Field |
| 2.07 |
Engineering and Technology |
Environmental engineering
|
land cadastre, cadastral monuments, ground markers, aerial photogrammetry, UAV, point cloud, ortophoto
Researchers (14)
Organisations (1)
Abstract
The main aim of the proposed project is to explore the possibilities of using remote sensing for the cadastral geospatial data acquisition. The project is focused on the use of optical sensors on Unmanned Aerial Vehicles – UAV for photogrammetric geospatial data acquisition. The focus of the project is on the optimization of the photogrammetric data acquisition for cadastral mapping. Cadastral points or boundary stones (hereinafter: cadastral points), as mentioned in this application, are the points that define the course of the cadastral parcel boundary or part of the cadastral parcel boundary; their position is being determined by the coordinates in the reference geodetic coordinate system.
Photogrammetric cadastral data acquisition is not a novelty in the land cadastre, as the first projects in Europe and at the wider international level appeared already in the 1950s. In particular, those projects should be understood as a consequence of the technological development in the field of optical geospatial acquisition of spatial data by airplanes. Even in Slovenia, there are several new photogrammetric cadastral surveys from this period, but the photogrammetric cadastral data acquisition has not been very well established in practice - the reason can be found in expensive aerial surveying. Recently, the main challenge in the field of photogrammetric cadastral mapping has been in the development of new platforms and technologies for geospatial data acquisition from the air, remote-controlled systems for geospatial data acquisition, known also as Unmanned Aerial Systems – UAS. The unexplored is the field of marking of ground control points and cadastral points in the field, which would allow optimization of the processing and interpretation of the acquired geospatial data.
The main objective of the project is to examine and evaluate the different ways of marking of ground control points and cadastral points for the purpose of UAV-cadastral mapping. The various ways of ground control and cadastral points’ marking will be examined mainly from the aspects of:
‒ The possibility (semi)automatic identification of targets (signals) for image processing of acquired geospatial data,
‒ The positional accuracy of point clouds and orthophoto, and
‒ The positional accuracy of cadastral points in the national geodetic reference system D96/TM.
On the basis of the literature review and the analyses of the latest scientific and applicative projects’ results at the national and international level, different ways of marking the ground control points and cadastral points for UAV-based photogrammetric cadastral mapping will be defined aiming to contribute to (semi)automatic detection of those points. The suitability of the selected methods for marking of ground control points and cadastral points for their (semi)automatic detection and data processing will be examined in three study areas:
‒ The first study area will be an area with a predominantly agricultural land cover and relief diversity;
‒ In addition to agricultural land, the second study area will include built-up land plots of rural settlements;
‒ The third study area will be an urban area with various types of land cover (periurban area with industrial land use).
The suitability of the proposed photogrammetric cadastral mapping using UAVs will be assessed by the analyses of the positional accuracy of check points. This will be done by the comparison of photogrammetric determined coordinates of the control points with the coordinates of determined using the conventional surveying methods (tachymetric, GNSS). Additionally, we will examine the economic advantages and disadvantages of the proposed approach in relation to the classical geodetic surveying for different types of areas from the land use perspective, the perspective of cadastral area size, as well as from the perspective of the cadastral instrument (new cadastral survey,
Significance for science
The topic of the proposed project is, as it is evident also from the literature review, extremely interesting in the wider international level. Updating of cadastral data, and in particular, the optimization of cadastral surveying in large-scale cadastral projects, such as new cadastral survey or land consolidation, is a huge challenge for developed as well as developing countries. The planned approach of a photogrammetric cadastral survey based on UAVs has a significant potential in the international scientific arena. Special attention has to be given to the foreseen development of the solution for targeting ground control points, check points and cadastral points (boundary stones) aiming to support their (semi)autonomous recognition and identification in the process of image processing.
Furthermore, the proposed holistic approach to assure the (positional) quality of photogrammetrically acquired geospatial data using UAVs is also to be emphasized. In this research field, mainly results of partial studies that address the quality parameters/factors in the selected part of the photogrammetric work-process from geospatial data acquisition, processing and to spatial data modelling, are known at the international level. Therefore, an important scientific and professional contribution of the project is expected also from the holistic approach to monitoring and assessing the quality of photogrammetric geospatial data acquisition using UAVs.
Significance for the country
Each of our activities is directly or indirectly related to geolocation that is to the land. In our living environment, various public and private interests to the land are present. In principle, the property right on land gives the right to use the land. However, this right is not an absolute right as it is limited by a number of legal provisions. Regardless of whether we consider the spatial boundaries of property rights or spatial boundaries of other rights, restrictions and responsibilities on land, quality data on real estate units, that is on land plots or parts of land plots, to which the rights and restrictions relate, are of high importance. One of the fundamental land databases is the (land) cadastre, which faces great challenges in Slovenia, in particular from the perspective of the heterogeneity of data quality. This is based on the fact that the origins of the land cadastre go back to the 19th century. Consequently, there is a great need for new cadastral mapping, which is extremely expensive if the classic terrestrial surveying methods are used.
The development of mass geospatial data acquisition technologies, including UAV-based photogrammetric survey, has brought new opportunities in the field of cadastral mapping. By the optimization of surveying procedures in the land cadastre, it is expected to contribute to the new cadastral surveying. The latter is not only important for areas where cadastral data is of low quality (especially rural and peri-urban areas), but also for areas where large-scale cadastral projects are being carried out aiming to optimize for example agricultural or environmental projects (rural land consolidation projects), to allocate infrastructure objects and new building plots (land re-adjustment projects). The results of the project will bring new opportunities for geodetic and geoinformatics companies. Namely, the developed and tested method will offer an innovative approach to cadastral mapping by cost and time optimization. This will bring new opportunities for large-scale cadastral projects, such as new cadastral survey, land consolidation and land re-adjustment. The recommendations that will result from the project will significantly contribute to the standardization of UAV-based photogrammetric geospatial data acquisition and image processing as well as to the standardization of quality assessment, which is in particular important for the surveying and geoinformation profession.
In addition to the importance for the surveying profession, it is worth highlighting the indirect benefits of the project for the economy. As it is emphasized also in the continuation of the project proposal, cadastral data of high quality is of utmost importance for many geospatial decisions. Based on the proposed optimization of cadastral mapping using UAV-based photogrammetric data acquisition, more activities might be expected in the field of new cadastral survey and land consolidation in Slovenia. The quality of cadastral data, however, will further on contribute to better geospatial decisions, which is of great importance for the development of the country.
Most important scientific results
Annual report
2020
Most important socioeconomically and culturally relevant results
Annual report
2020
