GPU Accelerated Parallel Computing for Estimating Continuous Sky view Factor Map

Mapping Intimacies ◽

10.21203/rs.3.rs-279602/v1 ◽

2021 ◽

Author(s):

xiaojiang li ◽

Guoqing Wang

Keyword(s):

Parallel Computing ◽

Ray Tracing ◽

Urban Climate ◽

Estimation Methods ◽

View Factor ◽

Processing Unit ◽

Sky View Factor ◽

Shadow Casting ◽

The City ◽

Climate Studies

Abstract The sky view factor (SVF) that represents the fraction of visible sky on a hemisphere or the percentage of radiation reaching the planar ground in the entire hemisphere’s input radiation is an important parameter for urban climate studies. However, the estimation of a continuous SVF map is very time-consuming, which limits the applications of SVF to small geographical areas. This study proposed to use graphics processing unit (GPU) parallel computing to accelerate the computing of SVF in the city of Philadelphia, Pennsylvania, USA. This study implemented and compared both the GPU-accelerated version and regular CPU version of two major methods for estimating continuous SVF maps, ray tracing-based algorithm and shadow casting-based algorithm based on the high-resolution building height model. Results show that the GPU-accelerated algorithms can reduce the time consumption dramatically and estimate the SVF map for the city of Philadelphia in less than 20 minutes on a personal computer with one NVIDIA GPU. The ray tracing-based algorithm has a much more efficiency increase than the shadow casting-based algorithm on GPU. The proposed method makes it possible to generate large-scale continuous SVF maps using regular personal computers with GPU. The proposed GPU-accelerated SVF estimation methods would benefit urban climate studies.

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Comparison of models calculating the sky view factor used for urban climate investigations

Theoretical and Applied Climatology ◽

10.1007/s00704-011-0402-3 ◽

2011 ◽

Vol 105 (3-4) ◽

pp. 521-527 ◽

Cited By ~ 43

Author(s):

Martin Hämmerle ◽

Tamás Gál ◽

János Unger ◽

Andreas Matzarakis

Keyword(s):

Urban Climate ◽

View Factor ◽

Sky View Factor

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GPU-Enabled Shadow Casting for Solar Potential Estimation in Large Urban Areas. Application to the Solar Cadaster of Greater Geneva

Applied Sciences ◽

10.3390/app10155361 ◽

2020 ◽

Vol 10 (15) ◽

pp. 5361

Author(s):

Nabil Stendardo ◽

Gilles Desthieux ◽

Nabil Abdennadher ◽

Peter Gallinelli

Keyword(s):

High Resolution ◽

Urban Areas ◽

Graphics Processing Units ◽

Large Scale ◽

View Factor ◽

Direct Sunlight ◽

Sky View Factor ◽

Shadow Casting ◽

Graphics Processing ◽

Better Than

In the context of encouraging the development of renewable energy, this paper deals with the description of a software solution for mapping out solar potential in a large scale and in high resolution. We leverage the performance provided by Graphics Processing Units (GPUs) to accelerate shadow casting procedures (used both for direct sunlight exposure and the sky view factor), as well as use off-the-shelf components to compute an average weather pattern for a given area. Application of the approach is presented in the context of the solar cadaster of Greater Geneva (2000 km2). The results show that doing the analysis on a square tile of 3.4 km at a resolution of 0.5 m takes up to two hours, which is better than what we were achieving with the previous work. This shows that GPU-based calculations are highly competitive in the field of solar potential modeling.

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O FATOR DE VISÃO DO CÉU E SUA INFLUÊNCIA SOBRE AS CARACTERÍSTICAS TÉRMICO-HIGROMÉTRICAS INTRAURBANAS EM PELOTAS/RS, BRASIL / The Sky View Factor and its Influence on the Intra-Urban Thermal-Hygrometric Features in Pelotas City-Rio Grande do Sul State...

Geographia Meridionalis ◽

10.15210/gm.v1i1.5716 ◽

2015 ◽

Vol 1 (1) ◽

pp. 160 ◽

Cited By ~ 1

Author(s):

Erika Colischonn ◽

Caio Vinícius De Oliveira Ferreira

Keyword(s):

Relative Humidity ◽

Urban Climate ◽

Rio Grande ◽

View Factor ◽

Rio Grande Do Sul ◽

Sky View Factor ◽

Several Variables ◽

Average Relative Humidity ◽

Calculated Average ◽

Made In

O clima urbano é resultado das ações de diversas variáveis, entre elas o fator de visão do céu (FVC). Este artigo apresenta incialmente a metodologia utilizada para calcular o fator de visão do céu em dez postos de coleta de temperatura e umidade do ar na cidade de Pelotas-RS e, na sequência, um estudo comparativo do comportamento da temperatura e da umidade relativa do ar entre estes mesmos dez locais. Os dados resultam de três períodos de registro no ano de 2014: o primeiro em agosto/setembro, o segundo em novembro, o terceiro em dezembro. Cada ponto de coleta consistiu num pequeno coletor eletrônico de dados de temperatura e umidade relativa do ar (ONSET - U23-001), disposto dentro de um abrigo fixo a um tripé distante 1,5 metros do chão, que registrou dados de 30 em 30 minutos. Os resultados mostram relação entre o microclima e o FVC. Nos levantamentos considerados os registros nos locais de maior obstrução foram em mais de 70% das vezes superiores à média. As áreas menos obstruídas também foram aquelas que apresentaram temperaturas mais baixas que a média. Os locais mais frios que a média também apresentaram umidade relativa do ar mais alta que a média.Palavras-chave: Fator de visão do céu, temperatura e umidade do ar. The Sky View Factor and its Influence on the Intra-Urban Thermal-Hygrometric Features in Pelotas City - Rio Grande do Sul State, BrazilABSTRACTUrban climate is the result from several variables, among them, there is the sky view factor (SVF). This article identifies the sky view factor (SVF) use in an urban climate study made in Pelotas, Brazil. The research compares the temperature and relative humidity behaviors in ten various sampling stations, based on data collected from them. The results were obtained from three recording periods held in 2014: the first from August/September, the second from November and the third from December. Each station was equipped with a temperature and humidity datalogging device (ONSET - U23 001). They were placed inside a radiation shield that was attatched to a tripod 1.5m above the ground, where each device would register data every 30 minutes. The results unveiled relations between the SVF and the microclimate. From the samples that were taken in consideration, places with high obstruction were, 70% of the time, above the calculated average. The places with low obstruction were also where the biggest amount of below-average data was found. In addition, the places that were colder than average were the ones presenting higher than average relative humidity rates.Key-words: sky view factor, air temperature, relative humidity.

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Sky View Factor footprints for urban climate modeling

Urban Climate ◽

10.1016/j.uclim.2018.05.004 ◽

2018 ◽

Vol 25 ◽

pp. 120-134 ◽

Cited By ~ 40

Author(s):

Ariane Middel ◽

Jonas Lukasczyk ◽

Ross Maciejewski ◽

Matthias Demuzere ◽

Matthias Roth

Keyword(s):

Climate Modeling ◽

Urban Climate ◽

View Factor ◽

Sky View Factor

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Comment Joël Noilhan a influencé la modélisation et les études en climat urbain

La Météorologie ◽

10.37053/lameteorologie-2020-0022 ◽

2020 ◽

pp. 093

Author(s):

Valéry Masson ◽

Aude Lemonsu

Keyword(s):

Energy Balance ◽

Urban Environment ◽

Urban Climate ◽

Urban Canopy ◽

International Expert ◽

Radiative Processes ◽

Sont Encore ◽

The City ◽

Climate Studies ◽

The Town

Bien que ce fait soit peu connu, Joël Noilhan a commencé sa carrière non pas dans l'étude de la végétation, mais dans celle du climat urbain. Ses résultats de thèse sur les échanges radiatifs entre les différentes faces d'un bâtiment, le ciel et le sol sont encore utilisés comme hypothèses dans la plupart des modèles de canopée urbaine, comme celui développé au CNRM, Town Energy Balance (TEB). Joël a contribué dans les années 2000 à l'essor de la météorologie urbaine au CNRM. Il a notamment encouragé les collaborations internationales avec l'équipe canadienne du professeur Tim Oke, spécialiste mondial du climat urbain, et initié un volet expérimental dédié à l'urbain sur la ville de Marseille, lors de la campagne Escompte en 2001. This is not well known, but Joël Noilhan did not start his career by studying vegetation processes, but rather urban climate. His PhD results on radiative exchanges around a building still form the basis of radiative processes in most urban canopy models such as the Town Energy Balance (TEB) developed at CNRM. In the 2000s, he contributed to the urban climate studies at CNRM. He encouraged an international collaboration with the team of Tim Oke, in Canada, an international expert in urban climate. He also initiated an experimental component dedicated to urban environment over the city of Marseille, during the Escompte campaign in 2001.

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