scholarly journals METHODS FOR THE UPDATE AND VERIFICATION OF FOREST SURFACE MODEL

2016 ◽  
Vol XLI-B4 ◽  
pp. 51-54
Author(s):  
M. Rybansky ◽  
M. Brenova ◽  
P. Zerzan ◽  
J. Simon ◽  
T. Mikita
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Geographic Location ◽  
Canopy Height ◽  
Aerial Photographs ◽  
Surface Model ◽  
Vegetation Growth ◽  
Terrain Model ◽  
Digital Terrain ◽  
Pulse Echo

The digital terrain model (DTM) represents the bare ground earth's surface without any objects like vegetation and buildings. In contrast to a DTM, Digital surface model (DSM) represents the earth's surface including all objects on it. The DTM mostly does not change as frequently as the DSM. The most important changes of the DSM are in the forest areas due to the vegetation growth. Using the LIDAR technology the canopy height model (CHM) is obtained by subtracting the DTM and the corresponding DSM. The DSM is calculated from the first pulse echo and DTM from the last pulse echo data. The main problem of the DSM and CHM data using is the actuality of the airborne laser scanning. <br><br> This paper describes the method of calculating the CHM and DSM data changes using the relations between the canopy height and age of trees. To get a present basic reference data model of the canopy height, the photogrammetric and trigonometric measurements of single trees were used. Comparing the heights of corresponding trees on the aerial photographs of various ages, the statistical sets of the tree growth rate were obtained. These statistical data and LIDAR data were compared with the growth curve of the spruce forest, which corresponds to a similar natural environment (soil quality, climate characteristics, geographic location, etc.) to get the updating characteristics.

scholarly journals METHODS FOR THE UPDATE AND VERIFICATION OF FOREST SURFACE MODEL

2016 ◽  
Vol XLI-B4 ◽  
pp. 51-54
Author(s):  
M. Rybansky ◽  
M. Brenova ◽  
P. Zerzan ◽  
J. Simon ◽  
T. Mikita
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Geographic Location ◽  
Canopy Height ◽  
Aerial Photographs ◽  
Surface Model ◽  
Vegetation Growth ◽  
Terrain Model ◽  
Digital Terrain ◽  
Pulse Echo

The digital terrain model (DTM) represents the bare ground earth's surface without any objects like vegetation and buildings. In contrast to a DTM, Digital surface model (DSM) represents the earth's surface including all objects on it. The DTM mostly does not change as frequently as the DSM. The most important changes of the DSM are in the forest areas due to the vegetation growth. Using the LIDAR technology the canopy height model (CHM) is obtained by subtracting the DTM and the corresponding DSM. The DSM is calculated from the first pulse echo and DTM from the last pulse echo data. The main problem of the DSM and CHM data using is the actuality of the airborne laser scanning. &lt;br&gt;&lt;br&gt; This paper describes the method of calculating the CHM and DSM data changes using the relations between the canopy height and age of trees. To get a present basic reference data model of the canopy height, the photogrammetric and trigonometric measurements of single trees were used. Comparing the heights of corresponding trees on the aerial photographs of various ages, the statistical sets of the tree growth rate were obtained. These statistical data and LIDAR data were compared with the growth curve of the spruce forest, which corresponds to a similar natural environment (soil quality, climate characteristics, geographic location, etc.) to get the updating characteristics.

scholarly journals Changes in a hydrographic network of the Słowiński National Park in terms of photogrammetric analyses

2017 ◽  
Vol 21 (4) ◽  
pp. 197-204
Author(s):  
Maciej Góraj ◽  
Marcin Kucharski ◽  
Krzysztof Karsznia ◽  
Izabela Karsznia ◽  
Jarosław Chormański
Keyword(s):  
Spatial Data ◽  
National Park ◽  
Laser Scanning ◽  
Digital Terrain Model ◽  
Aerial Photographs ◽  
Terrain Model ◽  
Digital Terrain ◽  
Protected Natural Area ◽  
Water Courses ◽  
Hydrographic Network

AbstractThe main objective of this study is to evaluate the changes in the hydrographic network of Słowiński National Park. The authors analysed the changes occurring in the drainage network due to limited maintenance in this legally protected natural area. To accomplish this task, elaborations prepared on the basis of aerial photographs were used: an orthophoto map from 1996, hyperspectral imaging from June 2015, and a digital terrain model based on airborne laser scanning (ALS) from June 2015. These spatial data resources enabled the digitisation of the water courses for which selected hydro-morphological features had been defined. As a result of analysing the differences of these features, a quality map was elaborated which was then subjected to interpretation, and the identified changes were quantified in detail.

scholarly journals MODELING CITIES FOR 3D_GIS PURPOSES

2018 ◽  
Vol XLII-4 ◽  
pp. 135-142
Author(s):  
E. G. V. de Jesus ◽  
A. L. de Amorim ◽  
N. J. Groetelaars ◽  
V. O. Fernandes
Keyword(s):  
Data Model ◽  
Geometric Modeling ◽  
Laser Scanning ◽  
Semantic Representation ◽  
Digital Terrain Model ◽  
Surface Model ◽  
Geography Markup Language ◽  
Terrain Model ◽  
Digital Terrain ◽  
First Results

<p><strong>Abstract.</strong> 3D Geographic Information Systems (3D GIS) are systems that are capable of making spatial analyses that consider the tridimentional and semantic representation of objects. These systems make these analyses through its planialtimetric coordinates. The City Geography Markup Language (CityGML) is used for the representation of cities and urban applications. The CityGML is an international standardized data model based on XML used to store and exchange information through 3D representation of cities. This standardized data model has 5 Levels of Detail – LOD, varying from LOD 0 (least detailed) to 4 (most detailed). The main challenges for the implementation of these systems refer to the techniques used for obtaining data and the data format, and also all the software used in the geometric modeling of the urban model. The data related to the buildings were manipulated with the QGIS software in this study. This made it possible to obtain the height of the buildings by the elevation difference between the Digital Surface Model and the Digital Terrain Model. This paper presents and discusses the first results of the geometric modeling made in the campus of the Federal University of Bahia (UFBA), by using airborne laser scanning data, integrating QGIS, Rhinoceros and CityGML.</p>

scholarly journals DTM-based analysis of the spatial distribution of topolineaments

2020 ◽  
Vol 12 (1) ◽  
pp. 1185-1199
Author(s):  
Mirosław Kamiński
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Research Area ◽  
Tectonic Structures ◽  
Empirical Bayesian ◽  
Scanning Method ◽  
Empirical Bayesian Kriging ◽  
Terrain Model ◽  
Digital Terrain ◽  
Airborne Laser

AbstractThe research area is located on the boundary between two Paleozoic structural units: the Radom–Kraśnik Block and the Mazovian–Lublin Basin in the southeastern Poland. The tectonic structures are separated by the Ursynów–Kazimierz Dolny fault zone. The digital terrain model obtained by the ALS (Airborne Laser Scanning) method was used. Classification and filtration of an elevation point cloud were performed. Then, from the elevation points representing only surfaces, a digital terrain model was generated. The model was used to visually interpret the course of topolineaments and their automatic extraction from DTM. Two topolineament systems, trending NE–SW and NW–SE, were interpreted. Using the kernel density algorithm, topolineament density models were generated. Using the Empirical Bayesian Kriging, a thickness model of quaternary deposits was generated. A relationship was observed between the course of topolineaments and the distribution and thickness of Quaternary formations. The topolineaments were compared with fault directions marked on tectonic maps of the Paleozoic and Mesozoic. Data validation showed consistency between topolineaments and tectonic faults. The obtained results are encouraging for further research.

Improving the accuracy of forming a digital terrain model along the railway

2021 ◽  
pp. 22-29
Author(s):  
Dmitriy A. Roshchin
Keyword(s):  
High Efficiency ◽  
Digital Terrain Model ◽  
Digital Processing ◽  
Aerial Photographs ◽  
Railway Track ◽  
Technical Solution ◽  
Digital Terrain Models ◽  
Terrain Model ◽  
Digital Terrain ◽  
Terrain Models

The problem of improving the accuracy of digital terrain models created for monitoring and diagnostics of the railway track and the surrounding area is considered. A technical solution to this problem is presented, which includes a method for joint aerial photography and laser scanning, as well as a method for digital processing of the obtained data. The relevance of using this solution is due to the existence of zones of weak reception of signals from the global navigation satellite system, since in these zones the accuracy of constructing digital terrain models using currently used diagnostic spatial scanning systems is reduced. The technical solution is based on the method of digital processing of aerial photographs of the railway track. In this case, as elements of external orientation, the threads of the rail track located at a normalized distance from each other are used. The use of this method made it possible to increase the accuracy of determining the flight path of an aircraft over railway tracks and, as a result, the accuracy of calculating the coordinates of points on the earth's surface. As a result, a digital terrain model was created that is suitable for diagnostics and monitoring the condition of the railway trackbed. During simulation modeling, it was found that the application of the proposed method allowed to reduce to 50 % the confidence interval of the distribution of the error in determining the coordinates of points on the terrain and increase the accuracy of forming a digital terrain model. This promising technical solution for improving the accuracy of digital terrain models for railway track diagnostics is implemented using unmanned aerial vehicles that are part of the mobile diagnostic complex. The advantages of the proposed solution include high efficiency and availability of application.

scholarly journals Automated Generation of Digital Terrain Model using Point Clouds of Digital Surface Model in Forest Area

2011 ◽  
Vol 3 (5) ◽  
pp. 845-858 ◽  
Author(s):  
Kande R.M.U. Bandara ◽  
Lal Samarakoon ◽  
Rajendra P. Shrestha ◽  
Yoshikazu Kamiya
Keyword(s):  
Digital Terrain Model ◽  
Point Clouds ◽  
Forest Area ◽  
Surface Model ◽  
Digital Surface Model ◽  
Automated Generation ◽  
Terrain Model ◽  
Digital Terrain

scholarly journals TECHNIQUE OF AUTOMATIC MOBILE LASER SCANNING DATA FILTERING

2021 ◽  
Vol 26 (3) ◽  
pp. 5-19
Author(s):  
Maxim A. Altyntsev ◽  
◽  
Hamid Majid Saber Karkokli ◽  
Keyword(s):  
Laser Scanning ◽  
Single Point ◽  
Laser Scanner ◽  
Digital Terrain Model ◽  
Weather Conditions ◽  
Automatic Generation ◽  
Data Filtering ◽  
Terrain Model ◽  
Digital Terrain ◽  
Filtration Technique

The result of laser scanning is an array of laser points. The generation of a single point cloud in a given coordinate system is carried out during the registration process at the stage of preliminary field data processing. At this stage it is also often necessary to filter the data. Laser points with an erroneous position are eliminated during the data filleting. The number of erroneous laser points is determined by the of the laser scanner characteristics, surveyed area peculiarities and weather conditions. The devel-opment of methods and algorithms for filtering laser scanning data is carried out based on the analysis of the laser point spatial position and a certain set of additional characteristics, such as intensity value, echo signal, color value. The technique of mobile laser scanning data filtering for the territory of the road passing among the forest and close to individual industrial facilities and building. The main goal of the proposed filtration technique is to obtain data for automatic generation of an accurate digital terrain model. The filtration technique was developed for data acquired under the least favorable con-ditions – in wet weather. Accuracy estimation of generating digital terrain model based on filtered data was carried out.

Google Earth Revisited

2017 ◽  
Vol 1 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Dimitris Kaimaris ◽  
Petros Patias ◽  
Olga Georgoula
Keyword(s):  
Digital Terrain Model ◽  
Google Earth ◽  
Aerial Photographs ◽  
Editorial Team ◽  
Research Activity ◽  
Ongoing Research ◽  
Terrain Model ◽  
Digital Terrain ◽  
The City ◽  
Ongoing Research Activity

The interpretation of photos and the processing of Google Earth imagery which allowed the “random” discovery, as a result of a non-systematical research, of a numerous marks of buried constructions in the wide area of the city of Larisa (Thessaly, Greece) is presented in this project. Additional data as aerial photographs over time, satellite images and the digital terrain model of the same area has been used. From the numerous marks, this project mainly focuses on three positions where the positive marks (soilmarks or/and cropmarks), circular or/and linear, reveal on a satisfying level covered construction of great dimensions. The ongoing research activity of the editorial team along with this research highlights the advantages of using Google Earth imagery in an attempt to “random” mark of unknown covered constructions, or, in the frame of a systematic survey of aerial and remote sensing archaeology, as additional and not exclusive source of information.

scholarly journals Automating the creation of channel cross section data from aerial laser scanning and hydrological surveying for modeling flood events / Automatická tvorba geometrie vodních toků na základě syntézy dat z leteckého laserového skenování a hydrologického měření pro modelování povodňových událostí. j. hydrol., hydromech., 60, 2012, 4; 25 lit., 8 obr., 5 tab.

2012 ◽  
Vol 60 (4) ◽  
pp. 227-241 ◽  
Author(s):  
Radek Roub ◽  
Tomáš Hejduk ◽  
Pavel Novák
Keyword(s):  
Flow Rate ◽  
Hydrodynamic Model ◽  
Input Data ◽  
Laser Scanning ◽  
Digital Terrain Model ◽  
Flood Events ◽  
Hydrodynamic Models ◽  
Terrain Model ◽  
Aerial Laser Scanning ◽  
Digital Terrain

Knowing the extent of inundation areas for individual N-year flood events, the specific flood scenarios, and having an idea about the depths and velocities in the longitudinal or transverse water course profile provided by hydrodynamic models is of key importance for protecting peoples’ lives and mitigating damage to property. Input data for creating the watercourse computational geometry are crucial for hydrodynamic models. Requirements for input data vary with respect to the hydrodynamic model used. One-dimensional (1D) hydrodynamic models in which the computing track is formed by cross-sectional profiles of the channel are characterized by lower requirements for input data. In two-dimensional (2D) hydrodynamic models, a digital terrain model is needed for the entire area studied. Financial requirements of the project increase with regard to the input data and the model used. The increase is mainly due to the high cost of the geodetic surveying of the stream channel. The paper aims at a verification and presentation of the suitability of using hydrological measurements in developing a schematization (geometry) of water courses based on topographic data gained from aerial laser scanning provided by the Czech Office for Surveying, Mapping and Cadastre. Taking into account the hydrological measurement during the schematization of the water course into the hydrodynamic model consists in the derivation of flow rate achieved at the time of data acquisition using the method of aerial laser scanning by means of hydrological analogy and in using the established flow rate values as a basis for deepening of the digital terrain model from aerial laser scanning data. Thus, the given principle helps to capture precisely the remaining part of the channel profile which is not reflected in the digital terrain model prepared by the method of aerial laser scanning and fully correct geometry is achieved for the hydrodynamic model.

scholarly journals Threat of Pollution Hotspots Reworking in River Systems: Case Study of the Ploučnice River (Czech Republic)

2019 ◽  
Vol 8 (1) ◽  
pp. 37 ◽  
Author(s):  
Jitka Elznicová ◽  
Tomáš Matys Grygar ◽  
Jan Popelka ◽  
Martin Sikora ◽  
Petr Novák ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Terrain Model ◽  
Non Invasive ◽  
Digital Terrain ◽  
Quality Of Water ◽  
Lateral Channel ◽  
Floodplain Development ◽  
Channel Deposits

As fluvial pollution may endanger the quality of water and solids transported by rivers, mapping and evaluation of historically polluted fluvial sediments is an urgent topic. The Ploučnice River and its floodplain were polluted by local uranium mining from 1971–1989. We have studied this river since 2013 using a combination of diverse methods, including geoinformatics, to identify pollution hotspots in floodplains and to evaluate the potential for future reworking. Archival information on pollution history and past flooding was collected to understand floodplain dynamics and pollution heterogeneity. Subsequently, a digital terrain model based on laser scanning data and data analysis were used to identify the sites with river channel shifts. Finally, non-invasive geochemical mapping was employed, using portable X-ray fluorescence and gamma spectrometers. The resulting datasets were processed with geostatistical tools. One of the main outputs of the study was a detailed map of pollution distribution in the floodplain. The results showed a relationship between polluted sediment deposition, past channel shifts and floodplain development. We found that increased concentration of pollution occurred mainly in the cut-off meanders and lateral channel deposits from the mining period, the latter in danger of reworking (reconnecting to the river) in the coming decades.

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