On the effects of rough ground and atmospheric absorption on aircraft noise
The noise received from an aircraft is modified by atmospheric attenuation and reflections from the ground. The interference of direct and reflected waves is simplest for a flat ground, whereas multiple reflections can occur for rough ground or mountainous surroundings. The ground characteristics, l...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
De Gruyter
2022-03-01
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| Series: | Noise Mapping |
| Subjects: | |
| Online Access: | https://doi.org/10.1515/noise-2022-0003 |
| _version_ | 1811171931646328832 |
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| author | Campos Luiz Manuel Braga da Costa dos Santos Silva Manuel José de Sousa Oliveira João Manuel Gonçalves |
| author_facet | Campos Luiz Manuel Braga da Costa dos Santos Silva Manuel José de Sousa Oliveira João Manuel Gonçalves |
| author_sort | Campos Luiz Manuel Braga da Costa |
| collection | DOAJ |
| description | The noise received from an aircraft is modified by atmospheric attenuation and reflections from the ground. The interference of direct and reflected waves is simplest for a flat ground, whereas multiple reflections can occur for rough ground or mountainous surroundings. The ground characteristics, like reflection and absorption factors or impedance, also affect the received sound. All these effects have to be considered with respect to the path of the aircraft. Most of the literature about ground effects on aircraft noise considers a point source over a flat ground, using the method of images, that does not extend readily to rough ground. The effect of rough ground on aircraft noise can be modelled by: (i) identification of reflection points (there may be several points); (ii) use of a complex reflection coefficient (with amplitude and phase changes) at each reflection point; (iii) adding all reflected waves within line-of-sight of the receiver, that is not blocked by terrain (there is no blockage for a flat ground). |
| first_indexed | 2024-04-10T17:22:35Z |
| format | Article |
| id | doaj.art-45f94d952ea145a79eb27e81cf119acc |
| institution | Directory Open Access Journal |
| issn | 2084-879X |
| language | English |
| last_indexed | 2024-04-10T17:22:35Z |
| publishDate | 2022-03-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Noise Mapping |
| spelling | doaj.art-45f94d952ea145a79eb27e81cf119acc2023-02-05T08:27:17ZengDe GruyterNoise Mapping2084-879X2022-03-0191234710.1515/noise-2022-0003On the effects of rough ground and atmospheric absorption on aircraft noiseCampos Luiz Manuel Braga da Costa0dos Santos Silva Manuel José1de Sousa Oliveira João Manuel Gonçalves2CCTAE, IDMEC, LAETA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001, Lisboa, PortugalCCTAE, IDMEC, LAETA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001, Lisboa, PortugalCCTAE, IDMEC, LAETA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001, Lisboa, PortugalThe noise received from an aircraft is modified by atmospheric attenuation and reflections from the ground. The interference of direct and reflected waves is simplest for a flat ground, whereas multiple reflections can occur for rough ground or mountainous surroundings. The ground characteristics, like reflection and absorption factors or impedance, also affect the received sound. All these effects have to be considered with respect to the path of the aircraft. Most of the literature about ground effects on aircraft noise considers a point source over a flat ground, using the method of images, that does not extend readily to rough ground. The effect of rough ground on aircraft noise can be modelled by: (i) identification of reflection points (there may be several points); (ii) use of a complex reflection coefficient (with amplitude and phase changes) at each reflection point; (iii) adding all reflected waves within line-of-sight of the receiver, that is not blocked by terrain (there is no blockage for a flat ground).https://doi.org/10.1515/noise-2022-0003direct signalreflected signalground profileatmospheric attenuationmultipath factor |
| spellingShingle | Campos Luiz Manuel Braga da Costa dos Santos Silva Manuel José de Sousa Oliveira João Manuel Gonçalves On the effects of rough ground and atmospheric absorption on aircraft noise Noise Mapping direct signal reflected signal ground profile atmospheric attenuation multipath factor |
| title | On the effects of rough ground and atmospheric absorption on aircraft noise |
| title_full | On the effects of rough ground and atmospheric absorption on aircraft noise |
| title_fullStr | On the effects of rough ground and atmospheric absorption on aircraft noise |
| title_full_unstemmed | On the effects of rough ground and atmospheric absorption on aircraft noise |
| title_short | On the effects of rough ground and atmospheric absorption on aircraft noise |
| title_sort | on the effects of rough ground and atmospheric absorption on aircraft noise |
| topic | direct signal reflected signal ground profile atmospheric attenuation multipath factor |
| url | https://doi.org/10.1515/noise-2022-0003 |
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