scholarly journals A Novel Method for Feature Extraction and Classification for an Aerial Image and LiDAR Data with Genetic Algorithm

Author(s):  
Manjunath B. E ◽  
D. G. Anand ◽  
Mahant. G. Kattimani

Airborne Light Detection and Ranging (LiDAR) provides accurate height information for objects on the earth, which makes LiDAR become more and more popular in terrain and land surveying. In particular, LiDAR data offer vital and significant features for land-cover classification which is an important task in many application domains. Aerial photos with LiDAR data were processed with genetic algorithms not only for feature extraction but also for orthographical image. DSM provided by LiDAR reduced the amount of GCPs needed for the regular processing, thus the reason both efficiency and accuracy are highly improved. LiDAR is an acronym for Light Detection and Ranging, which is typically defined as an integration of three technologies into a single system, which is capable of acquiring a data to produce accurate Digital Elevation Models.

2021 ◽  
Vol 14 (1) ◽  
pp. 058
Author(s):  
Camila Gardenea de Almeida Bandim ◽  
Josiclêda Domiciano Galvíncio

O objetivo deste estudo consiste em avaliar as áreas inundáveis em Recife, com especial atenção à avenida Caxangá.  Iniciando uma análise sobre a drenagem convencional utilizando a tecnologia LIDAR (Light Detection And Ranging). Os dados empregados neste trabalho foram captados pelo sistema LIDAR e possuem 50 cm de resolução, sendo um total de 12 quadrículas xyz para a constituição do mosaico Modelo Digital de Elevação (MDE) da avenida Caxangá, com destaque para as quadrículas 81_50-05 e 81_60-05, partindo dessas foram geradas as direções e acúmulos de fluxo. Os resultados obtidos enfatizam a alta resolução através da nítida visualização de elementos naturais e artificiais, e ainda o nivelamento do terreno. Em seguida, observa-se o acúmulo de fluxo que exibe as diferentes direções e acúmulos do escoamento superficial, ainda se percebe a influência na drenagem urbana das construções antrópicas e da vegetação em locais pontuais da avenida Caxangá. Em conclusão os dados do sistema LIDAR responderam positivamente, tanto na captação na modelagem do terreno e topografia artificial, como também para as gerações de direções e acúmulo de fluxos apresentando maiores valores para áreas depressivas naturais e antropizadas. Sendo destaque neste estudo as áreas antropizadas por provocarem problemas de desastres naturais. Conclui-se que as áreas antropizadas exercem um importante papel na drenagem urbana.  Mapping water storage areas in depression, using LIDAR data: Caxangá Avenida case study A B S T R A C TThe objective of this study is to evaluate the floodable areas in Recife, with special attention to Avenida Caxangá. Starting an analysis on conventional drainage using LIDAR (Light Detection And Ranging) technology. The data used in this work were captured by the LIDAR system and have 50 cm of resolution, with a total of 12 xyz squares for the constitution of the Digital Elevation Model (MDE) mosaic on Avenida Caxangá, with emphasis on the squares 81_50-05 and 81_60 -05, from these directions and flow accumulations were generated. The results obtained emphasize the high resolution through the clear visualization of natural and artificial elements, as well as the leveling of the terrain. Then, there is the accumulation of flow that shows the different directions and accumulations of runoff, the influence on the urban drainage of anthropic buildings and vegetation in specific places on Avenida Caxangá is still perceived. In conclusion, the data from the LIDAR system responded positively, both in capturing terrain modeling and artificial topography, as well as for generations of directions and accumulation of flows, presenting higher values for natural and anthropized depressive areas. Being highlighted in this study the areas anthropized because they cause problems of natural disasters. It is concluded that anthropized areas play an important role in urban drainage.Keywords: Geoprocessing. Remote sensing. Urbanization. Urban flood. drainage


2016 ◽  
Vol 4 (2) ◽  
pp. 192-204 ◽  
Author(s):  
Thomas G. Garrison ◽  
Dustin Richmond ◽  
Perry Naughton ◽  
Eric Lo ◽  
Sabrina Trinh ◽  
...  

AbstractArchaeological tunneling is a standard excavation strategy in Mesoamerica. The ancient Maya built new structures atop older ones that were no longer deemed usable, whether for logistical or ideological reasons. This means that as archaeologists excavate horizontal tunnels into ancient Maya structures, they are essentially moving back in time. As earlier constructions are encountered, these tunnels may deviate in many directions in order to document architectural remains. The resultant excavations often become intricate labyrinths, extending dozens of meters. Traditional forms of archaeological documentation, such as photographs, plan views, and profile drawings, are limited in their ability to convey the complexity of tunnel excavations. Terrestrial Lidar (light detection and ranging) instruments are able to generate precise 3D models of tunnel excavations. This article presents the results of a model created with a Faro™ Focus 3D 120 Scanner of tunneling excavations at the site of El Zotz, Guatemala. The lidar data document the excavations inside a large mortuary pyramid, including intricately decorated architecture from an Early Classic (A.D. 300–600) platform buried within the present form of the structure. Increased collaboration between archaeologists and scholars with technical expertise maximizes the effectiveness of 3D models, as does presenting digital results in tandem with traditional forms of documentation.


Author(s):  
C. Serifoglu ◽  
O. Gungor ◽  
V. Yilmaz

Digital Elevation Model (DEM) generation is one of the leading application areas in geomatics. Since a DEM represents the bare earth surface, the very first step of generating a DEM is to separate the ground and non-ground points, which is called ground filtering. Once the point cloud is filtered, the ground points are interpolated to generate the DEM. LiDAR (Light Detection and Ranging) point clouds have been used in many applications thanks to their success in representing the objects they belong to. Hence, in the literature, various ground filtering algorithms have been reported to filter the LiDAR data. Since the LiDAR data acquisition is still a costly process, using point clouds generated from the UAV images to produce DEMs is a reasonable alternative. In this study, point clouds with three different densities were generated from the aerial photos taken from a UAV (Unmanned Aerial Vehicle) to examine the effect of point density on filtering performance. The point clouds were then filtered by means of five different ground filtering algorithms as Progressive Morphological 1D (PM1D), Progressive Morphological 2D (PM2D), Maximum Local Slope (MLS), Elevation Threshold with Expand Window (ETEW) and Adaptive TIN (ATIN). The filtering performance of each algorithm was investigated qualitatively and quantitatively. The results indicated that the ATIN and PM2D algorithms showed the best overall ground filtering performances. The MLS and ETEW algorithms were found as the least successful ones. It was concluded that the point clouds generated from the UAVs can be a good alternative for LiDAR data.


2008 ◽  
Vol 84 (6) ◽  
pp. 827-839 ◽  
Author(s):  
M. Woods ◽  
K. Lim ◽  
P. Treitz

Models were developed to predict forest stand variables for common species of the Great Lakes – St. Lawrence forest of central Ontario, Canada from light detection and ranging (LiDAR) data. Stands that had undergone various ranges of partial harvesting or initial spacing treatments from multiple geographic sites were considered. A broad forest stratification was adopted and consisted of: (i) natural hardwoods; (ii) natural conifers; and (iii) plantation conifers. Stand top height (R2 = 0.96, 0.98, and 0.98); average height (R2 = 0.86, 0.76, and 0.98); basal area (R2 = 0.80, 0.80, and 0.85); volume (R2 = 0.89, 0.81, and 0.91); quadratic mean diameter (R2 = 0.80, 0.68, and 0.83); and density (R2 = 0.74, 0.71, and 0.73) were predicted from low density (i.e., 0.5 point m-2) LiDAR data for these 3 strata, respectively. Key words: light detection and ranging, LiDAR, airborne laser scanning, forest modelling, remote sensing, forest stand variables, Great Lakes – St. Lawrence forest


2019 ◽  
Vol 11 (5) ◽  
pp. 550 ◽  
Author(s):  
Yunsong Li ◽  
Chiru Ge ◽  
Weiwei Sun ◽  
Jiangtao Peng ◽  
Qian Du ◽  
...  

A new method of superpixel segmentation-based local pixel neighborhood preserving embedding (SSLPNPE) is proposed for the fusion of hyperspectral and light detection and ranging (LiDAR) data based on the extinction profiles (EPs), superpixel segmentation and local pixel neighborhood preserving embedding (LPNPE). A new workflow is proposed to calibrate the Goddard’s LiDAR, hyperspectral and thermal (G-LiHT) data, which allows our method to be applied to actual data. Specifically, EP features are extracted from both sources. Then, the derived features of each source are fused by the SSLPNPE. Using the labeled samples, the final label assignment is produced by a classifier. For the open standard experimental data and the actual data, experimental results prove that the proposed method is fast and effective in hyperspectral and LiDAR data fusion.


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