scholarly journals Ideal Angular Orientation of Selected 64-Channel Multi Beam Lidars for Mobile Mapping Systems

2020 ◽  
Vol 12 (3) ◽  
pp. 510
Author(s):  
Bashar Alsadik
Keyword(s):  
Autonomous Navigation ◽  
Orientation Angle ◽  
Single Beam ◽  
Ideal Orientation ◽  
Mapping System ◽  
Fair Comparison ◽  
Mobile Mapping Systems ◽  
Mapping Systems ◽  
The Ideal

Lidar technology is thriving nowadays for different applications mainly for autonomous navigation, mapping, and smart city technology. Lidars vary in different aspects and can be: multi beam, single beam, spinning, solid state, full 360 field of view FOV, single or multi pulse returns, and many other geometric and radiometric aspects. Users and developers in the mapping industry are continuously looking for new released Lidars having high properties of output density, coverage, and accuracy while keeping a lower cost. Accordingly, every Lidar type should be well evaluated for the final intended mapping aim. This evaluation is not easy to implement in practice because of the need to have all the investigated Lidars available in hand and integrated into a ready to use mapping system. Furthermore, to have a fair comparison; it is necessary to ensure the test applied in the same environment at the same travelling path among other conditions. In this paper, we are evaluating two state-of-the-art multi beam Lidar types: Ouster OS-1-64 and Hesai Pandar64 for mapping applications. The evaluation of the Lidar types is applied in a simulation environment which approximates reality. The paper shows the determination of the ideal orientation angle for the two Lidars by assessing the density, coverage, and accuracy and presenting clear performance quantifications and conclusions.

scholarly journals Performance Assessment of Mobile Laser Scanning Systems Using Velodyne Hdl-32e

2021 ◽  
Vol 1 (1) ◽  
pp. 28-33
Author(s):  
Bashar Alsadik
Keyword(s):  
Laser Scanning ◽  
Impact Analysis ◽  
Orientation Angle ◽  
Point Clouds ◽  
Mobile Mapping ◽  
Ongoing Research ◽  
Mapping System ◽  
Mobile Mapping System ◽  
Mobile Mapping Systems ◽  
Mapping Systems

Mapping systems using multi-beam LiDARs are widely used nowadays for different geospatial applications graduating from indoor projects to outdoor city-wide projects. These mobile mapping systems can be either ground-based or aerial-based systems and are mostly equipped with inertial navigation systems INS. The Velodyne HDL-32 LiDAR is a well-known 360° spinning multi-beam laser scanner that is widely used in outdoor and indoor mobile mapping systems. The performance of such LiDARs is an ongoing research topic which is quite important for the quality assurance and quality control topic. The performance of this LiDAR type is correlated to many factors either related to the device itself or the design of the mobile mapping system. Regarding design, most of the mapping systems are equipped with a single Velodyne HDL32 in a specific orientation angle which is different among the mapping systems manufacturers. The LiDAR orientation angle has a significant impact on the performance in terms of the density and coverage of the produced point clouds. Furthermore, during the lifetime of this multi-beam LiDAR, one or more beams may be defected and then either continue the production or returned to the manufacturer to be fixed which then cost time and money. In this paper, the design impact analysis of a mobile laser scanning (MLS) system equipped with a single Velodyne HDL-32E will be clarified and a clear relationship is given between the orientation angle of the LiDAR and the output density of points. The ideal angular orientation of a single Velodyne HDL-32E is found to be at 35° in a mobile mapping system. Furthermore, we investigated the degradation of points density when one of the 32 beams is defected and quantified the density loss percentage and to the best of our knowledge, this is not presented in literature before. It is found that a maximum of about 8% point density loss occurs on the ground and 4% on the facades when having a defected beam of the Velodyne HDL-32E.   

scholarly journals MOBILE MAPPING OF THE LA CORONA LAVATUBE ON LANZAROTE

2019 ◽  
Vol IV-2/W5 ◽  
pp. 381-387 ◽  
Author(s):  
H. A. Lauterbach ◽  
D. Borrmann ◽  
A. Nüchter ◽  
A. P. Rossi ◽  
V. Unnithan ◽  
...  
Keyword(s):  
Laser Scanner ◽  
Optimization Approach ◽  
Indoor Environments ◽  
Mobile Mapping ◽  
Trajectory Estimation ◽  
Mapping System ◽  
Laser Scanners ◽  
Mobile Mapping System ◽  
Mobile Mapping Systems ◽  
Mapping Systems

<p><strong>Abstract.</strong> Planetary surfaces consist of rough terrain and cave-like environments. Future planetary exploration demands for accurate mapping. However, recent backpack mobile mapping systems are mostly tested in structured, indoor environments. This paper evaluates the use of a backpack mobile mapping system in a cave-like environment. The experiments demonstrate the abilities of an continuous-time optimization approach by mapping part of a lavatube of the La Corona volcano system on Lanzarote. We compare two strategies for trajectory estimation relying either on 2D or 3D laser scanners and show that a 3D laser scanner substantially improved the final results.</p>

scholarly journals MONITORING CAPABILITIES OF A MOBILE MAPPING SYSTEM BASED ON NAVIGATION QUALITIES

2016 ◽  
Vol XLI-B1 ◽  
pp. 625-631 ◽  
Author(s):  
H. Jing ◽  
N. Slatcher ◽  
X. Meng ◽  
G. Hunter
Keyword(s):  
Change Detection ◽  
Point Clouds ◽  
Mobile Mapping ◽  
Mapping System ◽  
Short Period ◽  
Laser Scanners ◽  
Mobile Mapping System ◽  
Mobile Mapping Systems ◽  
Mapping Systems

Mobile mapping systems are becoming increasingly popular as they can build 3D models of the environment rapidly by using a laser scanner that is integrated with a navigation system. 3D mobile mapping has been widely used for applications such as 3D city modelling and mapping of the scanned environments. However, accurate mapping relies on not only the scanner’s performance but also on the quality of the navigation results (accuracy and robustness) . This paper discusses the potentials of using 3D mobile mapping systems for landscape change detection, that is traditionally carried out by terrestrial laser scanners that can be accurately geo-referenced at a static location to produce highly accurate dense point clouds. Yet compared to conventional surveying using terrestrial laser scanners, several advantages of mobile mapping systems can be identified. A large area can be monitored in a relatively short period, which enables high repeat frequency monitoring without having to set-up dedicated stations. However, current mobile mapping applications are limited by the quality of navigation results, especially in different environments. The change detection ability of mobile mapping systems is therefore significantly affected by the quality of the navigation results. This paper presents some data collected for the purpose of monitoring from a mobile platform. The datasets are analysed to address current potentials and difficulties. The change detection results are also presented based on the collected dataset. Results indicate the potentials of change detection using a mobile mapping system and suggestions to enhance quality and robustness.

scholarly journals MONITORING CAPABILITIES OF A MOBILE MAPPING SYSTEM BASED ON NAVIGATION QUALITIES

2016 ◽  
Vol XLI-B1 ◽  
pp. 625-631
Author(s):  
H. Jing ◽  
N. Slatcher ◽  
X. Meng ◽  
G. Hunter
Keyword(s):  
Change Detection ◽  
Point Clouds ◽  
Mobile Mapping ◽  
Mapping System ◽  
Short Period ◽  
Laser Scanners ◽  
Mobile Mapping System ◽  
Mobile Mapping Systems ◽  
Mapping Systems

Mobile mapping systems are becoming increasingly popular as they can build 3D models of the environment rapidly by using a laser scanner that is integrated with a navigation system. 3D mobile mapping has been widely used for applications such as 3D city modelling and mapping of the scanned environments. However, accurate mapping relies on not only the scanner’s performance but also on the quality of the navigation results (accuracy and robustness) . This paper discusses the potentials of using 3D mobile mapping systems for landscape change detection, that is traditionally carried out by terrestrial laser scanners that can be accurately geo-referenced at a static location to produce highly accurate dense point clouds. Yet compared to conventional surveying using terrestrial laser scanners, several advantages of mobile mapping systems can be identified. A large area can be monitored in a relatively short period, which enables high repeat frequency monitoring without having to set-up dedicated stations. However, current mobile mapping applications are limited by the quality of navigation results, especially in different environments. The change detection ability of mobile mapping systems is therefore significantly affected by the quality of the navigation results. This paper presents some data collected for the purpose of monitoring from a mobile platform. The datasets are analysed to address current potentials and difficulties. The change detection results are also presented based on the collected dataset. Results indicate the potentials of change detection using a mobile mapping system and suggestions to enhance quality and robustness.

scholarly journals THEORETICAL ACCURACY PREDICTION AND VALIDATION OF LOW-END AND HIGH-END MOBILE MAPPING SYSTEM IN URBAN, RESIDENTIAL AND RURAL AREAS

2019 ◽  
Vol XLII-2/W18 ◽  
pp. 121-128 ◽  
Author(s):  
L. Mattheuwsen ◽  
M. Bassier ◽  
M. Vergauwen
Keyword(s):  
Rural Areas ◽  
Mobile Mapping ◽  
Major Drawback ◽  
Mapping System ◽  
Accuracy Level ◽  
Mobile Mapping System ◽  
3D Information ◽  
Mobile Mapping Systems ◽  
Theoretical Accuracy ◽  
Mapping Systems

Abstract. Mobile mapping systems are increasingly being used for the acquisition of 3D information of the environment. Although these systems are very efficient in data capturing compared to more traditional methods, the high cost of high-end accurate mobile mapping systems is a major drawback. In contrast, the much cheaper low-end mobile mapping systems are more frequently used for less accurate projects where visualization is more important. In general, the achievable accuracy level is the driving factor that differentiates low-end from high-end systems. To determine this value, the sensor quality, calibration and GNSS reception quality should be reliably evaluated.In this paper, we present a theoretical accuracy model of a mobile mapping system that takes into account variable GNSS accuracy. The predicted accuracy level of low-end and high-end mobile mapping systems is evaluated in a comprehensive accuracy analysis. The absolute accuracy of the system is determined in three datasets in which GNSS reception quality varies between optimal, good and poor. Additionally, the relative accuracy of both systems is checked by comparison of control distances. The presented approach allows for a more general and robust accuracy prediction of mobile mapping systems in different circumstances.

Metabolic response to temperature stress in the Colombian freshwater crab Neostrengeria macropa (H. Milne Edwards, 1853) (Decapoda: Brachyura: Pseudothelphusidae)

2021 ◽  
Author(s):  
David M Hudson
Keyword(s):  
Metabolic Response ◽  
Infrastructure Development ◽  
Predator Prey ◽  
Temperature Range ◽  
Indicator Group ◽  
Response To Temperature ◽  
Performance Results ◽  
The City ◽  
The Ideal

Abstract Freshwater crustaceans are distributed throughout the montane and lowland areas of Colombia, and are therefore a useful indicator group for how aquatic species will respond to climate change. As such, metabolic determination of physiological performance was evaluated for the Colombian pseudothelphusid crab, Neostrengeria macropa (H. Milne Edwards, 1853), over a temperature range inclusive of current temperatures and those predicted by future scenarios in the plateau around the city of Bogotá, namely from 8 °C to 30 °C. The performance results mostly aligned with previous exploratory behavioral determination of the ideal temperature range in the same species, although the metabolism increased at the highest temperature treatments, a point when exploratory behavior declined. These results indicate that this species of montane crab behaviorally compensates for increased thermal stress by decreasing its physical activity, which could have negative predator-prey consequences with changes to community structure as different species undergo climate-mediated geographic range shifts in the region. As this species is endemic to the plateau surrounding Bogotá, it also experiences a number of other stressors to its survival, including infrastructure development and invasive species.

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

scholarly journals Extraction of Guardrails from MMS Data Using Convolutional Neural Network

2021 ◽  
Vol 15 (3) ◽  
pp. 258-267
Author(s):  
Hiroki Matsumoto ◽  
◽  
Yuma Mori ◽  
Hiroshi Masuda
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Asset Management ◽  
Extraction Method ◽  
Point Clouds ◽  
Mobile Mapping ◽  
Method Point ◽  
Mobile Mapping Systems ◽  
Capture Point ◽  
Mapping Systems

Mobile mapping systems can capture point clouds and digital images of roadside objects. Such data are useful for maintenance, asset management, and 3D map creation. In this paper, we discuss methods for extracting guardrails that separate roadways and walkways. Since there are various shape patterns for guardrails in Japan, flexible methods are required for extracting them. We propose a new extraction method based on point processing and a convolutional neural network (CNN). In our method, point clouds and images are segmented into small fragments, and their features are extracted using CNNs for images and point clouds. Then, features from images and point clouds are combined and investigated using whether they are guardrails or not. Based on our experiments, our method could extract guardrails from point clouds with a high success rate.

scholarly journals CLASSIFICATION OF RAILWAY ASSETS IN MOBILE MAPPING POINT CLOUDS

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 219-225
Author(s):  
M. Corongiu ◽  
A. Masiero ◽  
G. Tucci
Keyword(s):  
Spatial Information ◽  
Point Clouds ◽  
Railway Track ◽  
Neural Net ◽  
Mobile Mapping ◽  
Geospatial Information ◽  
Railway System ◽  
Point Neighborhood ◽  
Mobile Mapping Systems ◽  
Mapping Systems

Abstract. Nowadays, mobile mapping systems are widely used to quickly collect reliable geospatial information of relatively large areas: thanks to such characteristics, the number of applications and fields exploiting their usage is continuously increasing. Among such possible applications, mobile mapping systems have been recently considered also by railway system managers to quickly produce and update a database of the geospatial features of such system, also called assets. Despite several vehicles, devices and acquisition methods can be considered for the data collection of the railway system, the predominant one is probably that based on the use of a mobile mapping system mounted on a train, which moves all along the railway tracks, enabling the 3D reproduction of the entire railway track area.Given the large amount of data collected by such mobile mapping, automatic procedures have to be used to speed up the process of extracting the spatial information of interest, i.e. assets positions and characteristics.This paper considers the problem of extracting such information for what concerns cantilever and portal masts, by exploiting a mixed approach. First, a set of candidate areas are extracted and pre-processed by considering certain of their geometric characteristics, mainly extracted by using eigenvalues of the covariance matrix of a point neighborhood. Then, a 3D modified Fisher vector-deep learning neural net is used to classify the candidates. Tests on such approach are conducted in two areas of the Italian railway system.

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