10 research outputs found
The analysis of possibility of creating of terrestrial orthophoto
Photogrammetry is the science of creating 2D or 3D models of object basing on several photo images. With the modern digital technologies it can be widely implemented for different tasks such as constructions and structures measurement, reverse engineering of curved surfaces etc. Photogrammetric measurements with the high speed cameras can be also implemented for measurements of vibrations. One of the intermediate stages of photogrammetric data evaluation used for 2D measurements and storing the obtained information is an orthophoto image. Here in this paper a short review of the principles and possibilities of the photogrammetric data acquisition are presented. Also the creation of orthophoto and basic 3D surface model of the manor-house ceiling performed by means of Canon EOS 1D Mark III camera and PhotoMod photogrammetric software is describe
Analysis and Identification of Abandoned Agricultural Land using the Remote Sensing Methodology
The problems of management of abandoned agricultural land as well as their effective use are relevant for any country to a greater or lesser extent. The endeavours to tackle the problems of effective utilization of abandoned agricultural land and in various ways are made in Lithuania as well as elsewhere. While analyzing the issues related to abandoned agricultural land, a clear definition of an abandoned area is important to perceive as well as potential methods for the identification of such areas are needed to analyse. Also, in order to suggest an effecticve utilisation of abandoned agricultural land for sustainable land use in the country, the analysis and statistics of such land is important to undertake.
The paper discusses the analysis of abandoned agricultural land in Lithuania, providing the dynamics of changes of abandoned agricultural land and the the percentage distribution of such land across Lithuania. Also, the factors, which caused the abonded agricultural land appearance in Lithuania identified and described. The Remote Sensing method identified and analysed as the most effective methodology for abandoned agricultural land identification. A collection of spatial data on abandoned agricultural land was formed on the base of spectral images of the terrene obtained from an artificial Earth satellite and a map of abandoned agricultural areas was created upon applying remote cartographic methods
CLOSE-RANGE PHOTOGRAMMETRY ENABLES DOCUMENTATION OF ENVIRONMENT-INDUCED DEFORMATION OF ARCHITECTURAL HERITAGE
Deformation, damage and permanent loss of heritage assets due to various physical and environmental factors has always been a major problem. As the availability of funds for conservation and restoration is limited, the digital documentation of heritage objects and monitoring of environment-induced deformations are increasingly important for cultural heritage preservation. Our study elucidates developments in the digital image capturing and processing for recording architectural heritage objects focusing on the digital camera calibration, close-range imaging, and photogrammetric modelling of complex structures using image matching techniques. A particular consideration in this paper is given to the ortho-photographic image compiling and accuracy assessment procedure. The practicality of the methodology is demonstrated by applying photogrammetric system PhotoMod for documentation of decorative elements in Uzutrakis manor, a national heritage site in Trakai, Lithuania
PHOTOGRAMMETRIC MEASUREMENTS OF HERITAGE OBJECTS
Cultural heritage is an invaluable example of human culture and creativity. The majority of them can become unstable or can be destroyed due to a combination of human and natural disturbances. In order to restore, preserve, and systematize data about architectural heritage objects, it is necessary to have geodetic, photogrammetric measurements of such data and to constantly monitor condition of the objects. The data of immovable cultural objects for many years are stored in photogrammetric data archives. Such archives have Germany, Lithuania, England and other countries. The article gives a brief introduction of the history of data archives formation and presents a photogrammetric and modern methods of modelling the spatial geometric properties of objects currently used to reveal immovable cultural properties and to evaluate geometric sizes. The pilot work was done with the Concept Capture simulation program that was developed by the Bentley company with photos of the Blessed Virgin Mary painting in Pivašiūnai of Trakai district. A shot from the ground with 12.4 MP resolution Pentax K-x camera was done using lenses with different focal lengths. The painting of the Blessed Virgin Mary is coordinated by 4 reference geodesic points and therefore after the modelling work it was possible to evaluate the accuracy of the created model. Based on the results of the spatial (3D) model, photo shooting and modelling recommendations are presented, the advantages of the new technology are distinguished
PHOTOGRAMMETRIC MEASUREMENTS OF HERITAGE OBJECTS
Cultural heritage is an invaluable example of human culture and creativity. The majority of them can become unstable or can be destroyed due to a combination of human and natural disturbances. In order to restore, preserve, and systematize data about architectural heritage objects, it is necessary to have geodetic, photogrammetric measurements of such data and to constantly monitor condition of the objects. The data of immovable cultural objects for many years are stored in photogrammetric data archives. Such archives have Germany, Lithuania, England and other countries. The article gives a brief introduction of the history of data archives formation and presents a photogrammetric and modern methods of modelling the spatial geometric properties of objects currently used to reveal immovable cultural properties and to evaluate geometric sizes. The pilot work was done with the Concept Capture simulation program that was developed by the Bentley company with photos of the Blessed Virgin Mary painting in Pivašiūnai of Trakai district. A shot from the ground with 12.4 MP resolution Pentax K-x camera was done using lenses with different focal lengths. The painting of the Blessed Virgin Mary is coordinated by 4 reference geodesic points and therefore after the modelling work it was possible to evaluate the accuracy of the created model. Based on the results of the spatial (3D) model, photo shooting and modelling recommendations are presented, the advantages of the new technology are distinguished
IMPLEMENTATION AND TESTING OF LOW COST UAV PLATFORM FOR ORTHOPHOTO IMAGING
Implementation of Unmanned Aerial Vehicles for civilian applications is rapidly increasing. Technologies which were expensive and
available only for military use have recently spread on civilian market. There is a vast number of low cost open source components
and systems for implementation on UAVs available. Using of low cost hobby and open source components ensures considerable
decrease of UAV price, though in some cases compromising its reliability.
In Space Science and Technology Institute (SSTI) in collaboration with Vilnius Gediminas Technical University (VGTU) researches
have been performed in field of constructing and implementation of small UAVs composed of low cost open source components
(and own developments). Most obvious and simple implementation of such UAVs – orthophoto imaging with data download and
processing after the flight.
The construction, implementation of UAVs, flight experience, data processing and data implementation will be further covered in the
paper and presentation
Unmanned Aerial Vehicles for Photogrammetry: Analysis of Orthophoto Images over the Territory of Lithuania
It has been recently observed that aircrafts tend to be replaced by light, simple structure unmanned aerial vehicles (UAV) or mini unmanned aerial vehicles (MUAV) with the purpose of updating the field of aerial photogrammetry. The built-in digital photo camera takes images of the Earth’s surface. To satisfy the photogrammetric requirements of the photographic images, it is necessary to carry out the terrestrial project planning of the flight path before the flight, to select the appropriate flying height, the time for acquiring images, the speed of the UAV, and other parameters. The paper presents the results of project calculations concerning the UAV flights and the analysis of the terrestrial images acquired during the field-testing flights. The experience carried out so far in the Lithuanian landscape is shown. The taken images have been processed by PhotoMod photogrammetric system. The paper presents the results of calculation of the project values of the UAV flights taking the images by digital camera Canon S100 and the analysis of the possibilities of the UAV orthophoto images’ mode
Geodata source retrieval by multilingual/semantic query expansion: the Case of Google Translate and WordNet version 3.1
In this article, we examined the potential of the current version of WordNet and Google Translate API to enhance the quality of geodata source retrieval in the Dutch geoinformation portal (PDOK) using semantic keywords for the geographic phenomena requested. Keywords gathered from real users’ questions in natural language extracted in an English corpus. Then, these keywords were expanded using WordNet and Google Translate API. Lastly, the results of query expansion were evaluated compared to a manual gold standard and based on information retrieval metrics. Our study shows that the results of query expansion help users by reformulating good alternative queries
Geodata source retrieval by multilingual/semantic query expansion: the Case of Google Translate and WordNet version 3.1
In this article, we examined the potential of the current version of WordNet and Google Translate API to enhance the quality of geodata source retrieval in the Dutch geoinformation portal (PDOK) using semantic keywords for the geographic phenomena requested. Keywords gathered from real users’ questions in natural language extracted in an English corpus. Then, these keywords were expanded using WordNet and Google Translate API. Lastly, the results of query expansion were evaluated compared to a manual gold standard and based on information retrieval metrics. Our study shows that the results of query expansion help users by reformulating good alternative queries