Chaos in Motion: Measuring Visual Pollution with Tangential View Landscape Metrics

Visual pollution (VP) in the form of outdoor advertisements (OA) is a threat to landscape physiognomy. Despite their proven usefulness in landscape aesthetic studies, landscape metrics have not yet been applied to address the phenomenon of VP. To fill this knowledge gap, a methodological framework for the measurement of VP using tangential view landscape metrics is proposed, which is accompanied by statistically significant proofs. Raster products derived from aerial laser scanning data were used to characterize two study areas with different topographic conditions in the city of Lublin, East Poland. The visibility of the cityscape in motion was simulated through viewshed measurements taken at equal intervals in the forwards and backwards directions along pedestrian walkways. The scrutinized tangential view landscape metrics (visible area, maximum visible distance, skyline, Shannon depth, view depth line) was the object of a two-fold interpretation wherein the spatial occurrence of VP as well as its impacts on the visual landscape character (VLC) were examined. The visible area metrics were found to be highly sensitive VP indicators. The maximum visible distance metrics provided evidence for the destructive effect of OA on view corridors. The Shannon depth and depth line metrics were not found to be statistically significant indicators of VP. Results from directional viewshed modelling indicate that distortion in the analyzed cityscape physiognomy depends on the view direction. The findings allow for particular recommendations with practical implementations in land use planning, which are discussed along with limitations to our proposed methods.

Download Full-text

Aspects of Aerial Laser Scanning when exploring unknown archaeological sites (Case study)

Transportation Research Procedia ◽

10.1016/j.trpro.2017.12.166 ◽

2017 ◽

Vol 28 ◽

pp. 37-44 ◽

Cited By ~ 3

Author(s):

Peter Bobáľ ◽

Slavomír Sipina ◽

Filip Škultéty

Keyword(s):

Laser Scanning ◽

Archaeological Sites ◽

Aerial Laser Scanning

Download Full-text

Augmentation of Traditional Forest Inventory and Airborne Laser Scanning with Unmanned Aerial Systems and Photogrammetry for Forest Monitoring

Remote Sensing ◽

10.3390/rs10101562 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1562 ◽

Cited By ~ 17

Author(s):

Kathryn Fankhauser ◽

Nikolay Strigul ◽

Demetrios Gatziolis

Keyword(s):

Laser Scanning ◽

Canopy Cover ◽

Tree Height ◽

Forest Monitoring ◽

Unmanned Aerial Systems ◽

Aerial Laser Scanning ◽

Forest Inventories ◽

Airborne Laser ◽

Aerial Systems

Forest inventories are constrained by resource-intensive fieldwork, while unmanned aerial systems (UASs) offer rapid, reliable, and replicable data collection and processing. This research leverages advancements in photogrammetry and market sensors and platforms to incorporate a UAS-based approach into existing forestry monitoring schemes. Digital imagery from a UAS was collected, photogrammetrically processed, and compared to in situ and aerial laser scanning (ALS)-derived plot tree counts and heights on a subsample of national forest plots in Oregon. UAS- and ALS-estimated tree counts agreed with each other (r2 = 0.96) and with field data (ALS r2 = 0.93, UAS r2 = 0.84). UAS photogrammetry also reasonably approximated mean plot tree height achieved by the field inventory (r2 = 0.82, RMSE = 2.92 m) and by ALS (r2 = 0.97, RMSE = 1.04 m). The use of both nadir-oriented and oblique UAS imagery as well as the availability of ALS-derived terrain descriptions likely sustain a robust performance of our approach across classes of canopy cover and tree height. It is possible to draw similar conclusions from any of the methods, suggesting that the efficient and responsive UAS method can enhance field measurement and ALS in longitudinal inventories. Additionally, advancing UAS technology and photogrammetry allows diverse users access to forest data and integrates updated methodologies with traditional forest monitoring.

Download Full-text

Geodetic and Architectural Inventory of the Historic Wooden Church of St. Szczepan in Mnichów (Poland) in Terms of Safety Assessment of the Geometric Condition of the Structure.

10.21203/rs.3.rs-107843/v1 ◽

2020 ◽

Author(s):

Tomasz Lipecki

Keyword(s):

Laser Scanning ◽

Structural Changes ◽

18Th Century ◽

Good Condition ◽

Geometric Condition ◽

Mining Operations ◽

Destructive Effect ◽

Scanning Method ◽

3D Solid ◽

The Church

Abstract The article concerns the method of architectural inventory of the historic, wooden church in Mnichów (southern Poland), built in the 18th century. During hundreds of years of operation, structural changes can be seen in it, as well as in objects located above mining operations. The article explains the principles of inventory and describes the applied method of laser scanning, starting from the design to the creation of a 3D solid model of the object, paying particular attention to the analysis based on the created point cloud. Thanks to them, the area and volumes of all rooms were determined, the verticality of columns supporting the church levels was assessed, the floor level and verticality of walls were determined, as well as the shape and level of the roof edges. Based on the research, it can be concluded that the church, as an example of a wooden religious monument, is in good condition. The detected deformations in this range do not have a destructive effect on the current state of the object, but it should be subjected to control measurements in a cyclical manner. The laser scanning method used allowed for a wide and accurate scope of the study of the geometry of the church structure, without the need to disorganize its equipment.

Download Full-text

Hierarchical Regularization of Building Boundaries in Noisy Aerial Laser Scanning and Photogrammetric Point Clouds

Remote Sensing ◽

10.3390/rs10121996 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1996 ◽

Cited By ~ 5

Author(s):

Linfu Xie ◽

Qing Zhu ◽

Han Hu ◽

Bo Wu ◽

Yuan Li ◽

...

Keyword(s):

Laser Scanning ◽

Point Clouds ◽

Normal Vector ◽

Aerial Laser Scanning ◽

Second Stage ◽

Boundary Points ◽

Planar Structures ◽

Markov Random ◽

Two Stages ◽

Method Show

Aerial laser scanning or photogrammetric point clouds are often noisy at building boundaries. In order to produce regularized polygons from such noisy point clouds, this study proposes a hierarchical regularization method for the boundary points. Beginning with detected planar structures from raw point clouds, two stages of regularization are employed. In the first stage, the boundary points of an individual plane are consolidated locally by shifting them along their refined normal vector to resist noise, and then grouped into piecewise smooth segments. In the second stage, global regularities among different segments from different planes are softly enforced through a labeling process, in which the same label represents parallel or orthogonal segments. This is formulated as a Markov random field and solved efficiently via graph cut. The performance of the proposed method is evaluated for extracting 2D footprints and 3D polygons of buildings in metropolitan area. The results reveal that the proposed method is superior to the state-of-art methods both qualitatively and quantitatively in compactness. The simplified polygons could fit the original boundary points with an average residuals of 0.2 m, and in the meantime reduce up to 90% complexities of the edges. The satisfactory performances of the proposed method show a promising potential for 3D reconstruction of polygonal models from noisy point clouds.

Download Full-text

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.

Journal of Hydrology and Hydromechanics ◽

10.2478/v10098-012-0020-5 ◽

2012 ◽

Vol 60 (4) ◽

pp. 227-241 ◽

Cited By ~ 5

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.

Download Full-text

Investigating the Impact of Digital Elevation Models on Sentinel-1 Backscatter and Coherence Observations

Remote Sensing ◽

10.3390/rs12183016 ◽

2020 ◽

Vol 12 (18) ◽

pp. 3016

Author(s):

Ignacio Borlaf-Mena ◽

Maurizio Santoro ◽

Ludovic Villard ◽

Ovidiu Badea ◽

Mihai Andrei Tanase

Keyword(s):

Remote Sensing ◽

Laser Scanning ◽

Digital Elevation Models ◽

Shuttle Radar Topography Mission ◽

Synthetic Aperture ◽

Mountainous Regions ◽

Aerial Laser Scanning ◽

Digital Elevation ◽

The Difference ◽

The Impact

Spaceborne remote sensing can track ecosystems changes thanks to continuous and systematic coverage at short revisit intervals. Active remote sensing from synthetic aperture radar (SAR) sensors allows day and night imaging as they are not affected by cloud cover and solar illumination and can capture unique information about its targets. However, SAR observations are affected by the coupled effect of viewing geometry and terrain topography. The study aims to assess the impact of global digital elevation models (DEMs) on the normalization of Sentinel-1 backscattered intensity and interferometric coherence. For each DEM, we analyzed the difference between orbit tracks, the difference with results obtained with a high-resolution local DEM, and the impact on land cover classification. Tests were carried out at two sites located in mountainous regions in Romania and Spain using the SRTM (Shuttle Radar Topography Mission, 30 m), AW3D (ALOS (Advanced Land Observation Satellite) World 3D, 30 m), TanDEM-X (12.5, 30, 90 m), and Spain national ALS (aerial laser scanning) based DEM (5 m resolution). The TanDEM-X DEM was the global DEM most suitable for topographic normalization, since it provided the smallest differences between orbital tracks, up to 3.5 dB smaller than with other DEMs for peak landform, and 1.4–1.9 dB for pit and valley landforms.

Download Full-text