scholarly journals Fast post-Doppler STAP with road map for traffic monitoring: overview and first results

2019 ◽  
Vol 17 ◽  
pp. 137-143
Author(s):  
André B. C. da Silva ◽  
Stefan V. Baumgartner ◽  
Alberto Moreira
Keyword(s):  
Road Traffic ◽  
A Priori ◽  
Weather Conditions ◽  
Radar Data ◽  
Traffic Monitoring ◽  
Hardware Complexity ◽  
Real Time Processing ◽  
Road Map ◽  
First Results ◽  
Elevation Model

Abstract. Synthetic aperture radar (SAR) is an efficient solution for road traffic monitoring due to its high spatial resolution and independence from daylight and weather conditions. In this sense, a number of ground moving target indication (GMTI) algorithms have been developed, whereas their robustness is often achieved with high costs, increased hardware complexity and high computational burden. This paper presents a fast GMTI processor that blends the powerful post-Doppler space-time adaptive processing (PD STAP) with an a priori known road map and digital elevation model (DEM). The algorithm presents great potential for real-time processing, decreased hardware complexity and low costs compared to state-of-the-art systems. It is tested using real 4-channel X-band radar data acquired with the DLR's airborne F-SAR.

scholarly journals Novel post-Doppler STAP with a priori knowledge information for traffic monitoring applications: basic idea and first results

2017 ◽  
Vol 15 ◽  
pp. 77-82 ◽  
Author(s):  
André B. C. da Silva ◽  
Stefan V. Baumgartner
Keyword(s):  
A Priori ◽  
Traffic Monitoring ◽  
A Priori Knowledge ◽  
Hardware Complexity ◽  
Real Time Processing ◽  
The Road ◽  
Knowledge Based ◽  
Monitoring Applications ◽  
First Results ◽  
Priori Knowledge

Abstract. This paper presents a novel a priori knowledge-based algorithm for traffic monitoring applications. The powerful post-Doppler space-time adaptive processing (PD STAP) is combined with a known road network obtained from the freely available OpenStreetMap (OSM) database. The road information is applied after the PD STAP for recognizing and rejecting false detections, and moreover, for repositioning the vehicles detected in the vicinity of the roads. The algorithm presents great potential for real-time processing, decreased hardware complexity and low costs compared to state-of-the-art systems. The processor was tested using real multi-channel data acquired by DLR's airborne system F-SAR. The experimental results are shown and discussed, and the novelties are highlighted (e.g., the benefits of using a priori knowledge information).

scholarly journals A model for weather-related traffic variations and accident probabilities on roads

2021 ◽  
Author(s):  
Nico Becker ◽  
Henning Rust ◽  
Uwe Ulbrich
Keyword(s):  
Linear Models ◽  
Road Traffic ◽  
Weather Conditions ◽  
Radar Data ◽  
Traffic Volume ◽  
Road Accidents ◽  
Wind Speeds ◽  
Predictive Skill ◽  
Accident Probability ◽  
Low Cloud

<p>Weather conditions affect both road traffic volume and the probability of road accidents. The aim of this study is improve the understanding of both effects as well as their interactions. In a first step, we develop generalized linear models for hourly road traffic counts at 1400 traffic stations on German federal roads and highways. It is distinguished between different vehicle types, including motorbikes, cars, delivery vans and trucks. Different meteorological variables are derived from reanalysis and radar data. The impacts of these variables on the predictive skill of the models is analyzed. In particular models for motorbike counts show large improvements, if meteorological predictors are added to the model. At weekends in the afternoon the mean squared errors of modeled motorbike counts are reduced by up to 60%. Temperatures around 25°C, no precipitation, low cloud cover and low wind speeds lead to the highest motorbike counts. In a second step, the information derived from the traffic models is used to improve models for hourly probabilities of road accidents. These models are based on police reports, which are available at the level of administrative districts, and can now explicitly take traffic volume into account. It is shown that in particular winter conditions like precipitation and freezing temperatures lead to a significant increase in accident probability. Especially the probabilities of roadway departures show an increase under such conditions. The models presented in this study are suitable for the integration in risk-based warning systems and have the potential to improve risk perception and behavior of warning recipients.</p>

scholarly journals Web Based Tools for Road Traffic Monitoring and Controlling System

2013 ◽  
Vol 8-9 ◽  
pp. 3-12 ◽  
Author(s):  
Camelia Avram ◽  
Adina Astilean ◽  
Radu Florin Miron
Keyword(s):  
User Interfaces ◽  
New Technologies ◽  
Road Traffic ◽  
Traffic Monitoring ◽  
Large Set ◽  
Monitoring And Control ◽  
Web Based ◽  
The Road ◽  
Road Map ◽  
Communication Devices

The Road Traffic Monitoring and Control System (RTMCS) presented in this paper is intended to offer support for the surveillance, control and monitoring of road networks. It integrates complex components in a modular, flexible and open structure in order to validate models that take into account real time constraints and include tools to simulate various traffic scenarios and communication technologies, WEB based virtual instrumentation, personalized user interfaces and relational data. The system can be used to change the configuration of the road map (to design new streets segments) or to visualize the results of the different traffic scenarios implying the tuning of various parameters. RTMCS also offers several advantages, one of the most important consisting of the possibility to choose different configuration and components using a web browser. An implementation variant, including suitable, promising new technologies, different maps configurations, communication devices and protocols and routing systems is presented and analyzed. A large set of experiments and the corresponding results highlight the functionality of the configurable virtual web instrument concept illustrated by the proposed system. Aspects regarding the possibility of a subsequent integration of new tools are also presented.

Towards 1-Ångstrom-resolution STEM

1993 ◽  
Vol 51 ◽  
pp. 996-997
Author(s):  
H.S. von Harrach ◽  
D.E. Jesson ◽  
S.J. Pennycook
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Phase Contrast ◽  
Spherical Aberration ◽  
A Priori ◽  
Dark Field ◽  
Image Resolution ◽  
Objective Lens ◽  
Annular Dark Field ◽  
First Results

Phase contrast TEM has been the leading technique for high resolution imaging of materials for many years, whilst STEM has been the principal method for high-resolution microanalysis. However, it was demonstrated many years ago that low angle dark-field STEM imaging is a priori capable of almost 50% higher point resolution than coherent bright-field imaging (i.e. phase contrast TEM or STEM). This advantage was not exploited until Pennycook developed the high-angle annular dark-field (ADF) technique which can provide an incoherent image showing both high image resolution and atomic number contrast.This paper describes the design and first results of a 300kV field-emission STEM (VG Microscopes HB603U) which has improved ADF STEM image resolution towards the 1 angstrom target. The instrument uses a cold field-emission gun, generating a 300 kV beam of up to 1 μA from an 11-stage accelerator. The beam is focussed on to the specimen by two condensers and a condenser-objective lens with a spherical aberration coefficient of 1.0 mm.

Road Traffic Monitoring

IEE Review ◽  
1989 ◽  
Vol 35 (5) ◽  
pp. 188
Author(s):  
P.L. Belcher
Keyword(s):  
Road Traffic ◽  
Traffic Monitoring

scholarly journals LPWAN-based hybrid backhaul communication for intelligent transportation systems: architecture and performance evaluation

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Taghi Shahgholi ◽  
Amir Sheikhahmadi ◽  
Keyhan Khamforoosh ◽  
Sadoon Azizi
Keyword(s):  
Low Power ◽  
Intelligent Transportation Systems ◽  
Intelligent Transportation System ◽  
Road Traffic ◽  
Intelligent Transportation ◽  
Traffic Monitoring ◽  
Transportation Systems ◽  
Area Network ◽  
Emergency Vehicle ◽  
Wide Area Network

AbstractIncreased number of the vehicles on the streets around the world has led to several problems including traffic congestion, emissions, and huge fuel consumption in many regions. With advances in wireless and traffic technologies, the Intelligent Transportation System (ITS) has been introduced as a viable solution for solving these problems by implementing more efficient use of the current infrastructures. In this paper, the possibility of using cellular-based Low-Power Wide-Area Network (LPWAN) communications, LTE-M and NB-IoT, for ITS applications has been investigated. LTE-M and NB-IoT are designed to provide long range, low power and low cost communication infrastructures and can be a promising option which has the potential to be employed immediately in real systems. In this paper, we have proposed an architecture to employ the LPWAN as a backhaul infrastructure for ITS and to understand the feasibility of the proposed model, two applications with low and high delay requirements have been examined: road traffic monitoring and emergency vehicle management. Then, the performance of using LTE-M and NB-IoT for providing backhaul communication infrastructure has been evaluated in a realistic simulation environment and compared for these two scenarios in terms of end-to-end latency per user. Simulation of Urban MObility has been used for realistic traffic generation and a Python-based program has been developed for evaluation of the communication system. The simulation results demonstrate the feasibility of using LPWAN for ITS backhaul infrastructure mostly in favor of the LTE-M over NB-IoT.

Night-time disability glare of constant-light LED traffic monitoring fill light

2021 ◽  
pp. 147715352098226
Author(s):  
X Cai ◽  
L Quan ◽  
J Wu ◽  
Y He
Keyword(s):  
Dynamic Range ◽  
Road Traffic ◽  
Reaction Times ◽  
High Dynamic Range ◽  
Luminance Contrast ◽  
Traffic Monitoring ◽  
Constant Light ◽  
Night Time ◽  
Disability Glare ◽  
Small Targets

Fill light, used to helps cameras capture road traffic conditions at night, can lead to serious visual consequences for drivers. Research on disability glare from LED fill light is scarce and therefore this study explored strategies for controlling disability glare of constant-light LED traffic monitoring fill light. The threshold increment was used as an index to evaluate disability glare. The effective disability glare area of LED traffic monitoring fill light was determined based on high dynamic range technology. According to visual efficacy theory, there is a relationship between disability glare conditions and reaction times. The influencing factors include background luminance, luminance contrast and fill light luminance. The results showed that disability glare was the most intense in a range of 20 m to 30 m in front of LED fill light. To reduce the effect of disability glare on drivers, luminance contrast between small targets and the road surface should be greater than 0.5. The fill light luminance should not be greater than 100,000 cd/m2.

scholarly journals A new bedrock and surface elevation dataset for modelling the Greenland ice sheet

2003 ◽  
Vol 37 ◽  
pp. 351-356 ◽  
Author(s):  
Jonathan L. Bamber ◽  
Duncan J. Baldwin ◽  
S. Prasad Gogineni
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Detailed Comparison ◽  
Radar Data ◽  
The Arctic ◽  
Small Scale ◽  
Surface Model ◽  
Rock Outcrops ◽  
Bed Topography ◽  
Elevation Model

AbstractA new digital elevation model of the surface of the Greenland ice sheet and surrounding rock outcrops has been produced from a comprehensive suite of satellite and airborne remote-sensing and cartographic datasets. The surface model has been regridded to a resolution of 5 km, and combined with a new ice-thickness grid derived from ice-penetrating radar data collected in the 1970s and 1990s. A further dataset, the International Bathymetric Chart of the Arctic Ocean, was used to extend the bed elevations to include the continental shelf. The new bed topography was compared with a previous version used for ice-sheet modelling. Near the margins of the ice sheet and, in particular, in the vicinity of small-scale features associated with outlet glaciers and rapid ice motion, significant differences were noted. This was highlighted by a detailed comparison of the bed topography around the northeast Greenland ice stream.

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