Long-term vehicle localization in urban environments based on pole landmarks extracted from 3-D lidar scans

The pandemic of coronavirus disease (COVID-19) led to the need for drastic control measures around the world to reduce the impact on the health of the population. The confinement of people in their homes resulted in a significant reduction in human activity at every level (economic, social, industrial, etc.), which was reflected in a decrease in environmental pollution levels. Studying the evolution of parameters, such as the level of environmental noise caused by vehicle traffic in urban environments, makes it possible to assess the impact of this type of measure. This paper presents a case study of the acoustic situation in Cáceres (Spain) during the restriction period by means of long-term acoustic measurements at various points of the city.

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CREATING MULTI-TEMPORAL MAPS OF URBAN ENVIRONMENTS FOR IMPROVED LOCALIZATION OF AUTONOMOUS VEHICLES

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b2-2020-317-2020 ◽

2020 ◽

Vol XLIII-B2-2020 ◽

pp. 317-323

Author(s):

J. Schachtschneider ◽

C. Brenner

Keyword(s):

Urban Areas ◽

Autonomous Vehicles ◽

Weather Conditions ◽

Point Clouds ◽

Urban Environments ◽

Seasonal Effects ◽

Data Set ◽

Multi Temporal ◽

One Year

Abstract. The development of automated and autonomous vehicles requires highly accurate long-term maps of the environment. Urban areas contain a large number of dynamic objects which change over time. Since a permanent observation of the environment is impossible and there will always be a first time visit of an unknown or changed area, a map of an urban environment needs to model such dynamics.In this work, we use LiDAR point clouds from a large long term measurement campaign to investigate temporal changes. The data set was recorded along a 20 km route in Hannover, Germany with a Mobile Mapping System over a period of one year in bi-weekly measurements. The data set covers a variety of different urban objects and areas, weather conditions and seasons. Based on this data set, we show how scene and seasonal effects influence the measurement likelihood, and that multi-temporal maps lead to the best positioning results.

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GPS and Stereovision-Based Visual Odometry: Application to Urban Scene Mapping and Intelligent Vehicle Localization

International Journal of Vehicular Technology ◽

10.1155/2011/439074 ◽

2011 ◽

Vol 2011 ◽

pp. 1-17 ◽

Cited By ~ 22

Author(s):

Lijun Wei ◽

Cindy Cappelle ◽

Yassine Ruichek ◽

Frédérick Zann

Keyword(s):

Feature Detection ◽

Reference Frames ◽

Estimation Method ◽

Ground Truth ◽

Urban Environments ◽

Relative Depth ◽

Gps Receiver ◽

Minimization Method ◽

Vehicle Localization ◽

Stereoscopic System

We propose an approach for vehicle localization in dense urban environments using a stereoscopic system and a GPS sensor. Stereoscopic system is used to capture the stereo video flow, to recover the environments, and to estimate the vehicle motion based on feature detection, matching, and triangulation from every image pair. A relative depth constraint is applied to eliminate the tracking couples which are inconsistent with the vehicle ego-motion. Then the optimal rotation and translation between the current and the reference frames are computed using an RANSAC based minimization method. Meanwhile, GPS positions are obtained by an on-board GPS receiver and periodically used to adjust the vehicle orientations and positions estimated by stereovision. The proposed method is tested with two real sequences obtained by a GEM vehicle equipped with a stereoscopic system and a RTK-GPS receiver. The results show that the vision/GPS integrated trajectory can fit the ground truth better than the vision-only method, especially for the vehicle orientation. And vice-versa, the stereovision-based motion estimation method can correct the GPS signal failures (e.g., GPS jumps) due to multipath problem or other noises.

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Performing “Moral Resistance”? Pro-Life and Pro-Choice Activism in Public Space

Space and Culture ◽

10.1177/1206331217697142 ◽

2017 ◽

Vol 20 (2) ◽

pp. 221-238 ◽

Cited By ~ 5

Author(s):

Lucy Jackson ◽

Gill Valentine

Keyword(s):

Public Space ◽

Urban Environments ◽

Grassroots Activism ◽

Reproductive Politics ◽

The Public ◽

Political Problem ◽

And Performance ◽

A Site ◽

The Impact

This article focuses on acts of resistance regarding reproductive politics in contemporary Britain. Drawing on empirical research this article investigates grassroots activism around a complex moral, social, and political problem. This article therefore focuses on a site of resistance in everyday urban environments, investigating the practice and performance involved. Identifying specifically the territory(ies) and territorialities of these specific sites of resistance, this article looks at how opposing groups negotiate conflict in public space in territorial, as well as habitual, ways. Second, the article focuses on questions around the impact, distinction, and novelty both in the immediate and long term of these acts of resistance for those in public space. Here, then, the focus shifts to the reactions to this particular form of protest and questions the “acceptability” of specific resistances in the public imaginary.

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Nest-site competition and killing by invasive parakeets cause the decline of a threatened bat population

Royal Society Open Science ◽

10.1098/rsos.172477 ◽

2018 ◽

Vol 5 (5) ◽

pp. 172477 ◽

Cited By ~ 21

Author(s):

Dailos Hernández-Brito ◽

Martina Carrete ◽

Carlos Ibáñez ◽

Javier Juste ◽

José L. Tella

Keyword(s):

Native Species ◽

Population Decline ◽

Urban Environments ◽

Strong Impact ◽

Long Term Effects ◽

Individual Fitness ◽

Tree Cavities ◽

Negative Impacts ◽

Site Competition

The identification of effects of invasive species is challenging owing to their multifaceted impacts on native biota. Negative impacts are most often reflected in individual fitness rather than in population dynamics of native species and are less expected in low-biodiversity habitats, such as urban environments. We report the long-term effects of invasive rose-ringed parakeets on the largest known population of a threatened bat species, the greater noctule, located in an urban park. Both species share preferences for the same tree cavities for breeding. While the number of parakeet nests increased by a factor of 20 in 14 years, the number of trees occupied by noctules declined by 81%. Parakeets occupied most cavities previously used by noctules, and spatial analyses showed that noctules tried to avoid cavities close to parakeets. Parakeets were highly aggressive towards noctules, trying to occupy their cavities, often resulting in noctule death. This led to a dramatic population decline, but also an unusual aggregation of the occupied trees, probably disrupting the complex social behaviour of this bat species. These results indicate a strong impact through site displacement and killing of competitors, and highlight the need for long-term research to identify unexpected impacts that would otherwise be overlooked.

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