GNSS is being widely used in different applications navigation. However, positioning greatly challenged by notorious multipath effects and non-line-of-sight (NLOS) receptions. The signal blockage reflection buildings cause these effects. In other words, the more urbanized city is, challenge on positioning. conventional mitigation approaches, such as sophisticated design of receiver correlator, ...

This study investigated the role of urban geometry and shading in improving pedestrians’ thermal comfort hot climate Ahvaz, Iran. Six canyons are selected Ahvaz. To determine outdoor range, micrometeorological measurements questionnaire survey were conducted July 2018. ENVI-met is used to investigate shadings. evaluate comfort, physiologically equivalent temperature (PET) calculated using RayMa...

The influence of vegetation on the concentrations of traffic pollutants in urban street canyons is examined using numerical simulations with the CFD code OpenFOAM. This CFD approach is validated against literature wind tunnel data on traffic pollutant dispersion in street canyons. The impact of avenues of trees is simulated for a variety of vegetation types and the full range of approaching win...

The focus is the analysis of urban Digital Elevation Models (DEMs) with image processing techniques. A brief review of existing methods to derive sky view factors, building energy consumption and space syntax shows how well established parameters that relate to airflow and dispersion (such as the height-to-width of urban canyons and the aerodynamic roughness length) can be calculated. Other mea...

This paper proposes a 3D LiDAR aided global navigation satellite system (GNSS) non-line-of-sight (NLOS) mitigation method due to both static buildings and dynamic objects. A sliding window map describing the environment of ego-vehicle is first generated, based on real-time point clouds from sensor. Subsequently, NLOS receptions are detected using proposed quick searching which eliminates relian...

Geometric context has been recognised as important high-level knowledge towards the goal of scene understanding. In this work we present two approaches to estimate the local geometric structure of urban street canyons captured from a head-mounted stereo camera. A dense disparity estimation is the only input for both approaches. First, we show how the left and right building facade can be obtain...

Interunit dispersion problems have been studied previously mainly through on-site measurements, wind tunnel tests, and CFD simulations. In this study, a scaled outdoor experiment was conducted to examine the interunit characteristics in consecutive two-dimensional street canyons. Tracer gas ( CO 2 ) continuously released simulate pollutant routes between rooms The reentry ratio analyzed reveal ...

The urban canyon albedo (UCA) quantifies the ability of street canyons to reflect solar radiation back sky. UCA is controlled by reflectance road and façades geometry. This study investigates variability in a typical residential area London its impact on outdoor indoor microclimates. results are based measurements real 1:10 physical model simulations using ENVImet v 4.4.6 EnergyPlus. Different ...

This paper addresses the problem of calculating the accurate position of a GNSS device operating in an urban canyon, where lines of sight (LOS) with navigation satellites are too few for accurate trilateration calculation. We introduce a post-processing refinement algorithm, which makes use of a 3D map of the city buildings as well as captured signals from all traceable navigation satellites. T...