Progress on the R4AsH triple frequency radar laboratory experiments for characterization of volcanic ash
Progress on the R4AsH triple frequency radar laboratory experiments for characterization of volcanic ash
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R4AsH三频雷达火山灰表征室内实验研究进展
DOI：
10.1117/12.2618751
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Macfarlane D
中科院分区：
文献类型：
--
作者：
Macfarlane D
由于细火山灰可以在全球范围内扩散，火山羽流对航空业构成全球风险。减灾依赖于对羽流随时间演变的预测。然而，羽流扩散模型中不确定性的主要来源仍然是喷发源参数的准确量化，称为“源项”，描述羽流特征并为扩散模型提供信息。这些参数包括颗粒尺寸分布 (PSD) 和注入大气中的灰颗粒浓度。使用单频雷达通过反射率测量来估计喷发羽流的源项取决于对 PSD 和浓度如何组合的假设。然而，所选择的假设是不明确的，例如，高浓度的较小颗粒可以产生与低浓度的较大颗粒相同的反射率。 R4AsH 是一款三频实验室 FMCW 雷达，可同时测量三个频率（10、35 和 94 GHz）的受控空气灰柱。还对色谱柱内的 PSD 进行同步光学测量，为分析提供信息。 R4AsH 实验的目的是开发一种三频反演算法，通过结合瑞利 - 米氏散射范围内的雷达反射率数据，能够同时检索灰烬 PSD 和颗粒浓度。继我们之前报道的系统设计之后，我们将介绍雷达系统性能的回顾以及计划于 2022 年春季/夏季进行的 R4AsH 实验的初步测试。
Volcanic plumes pose a global risk to aviation, due to fine ash that can be dispersed over a global scale. Hazard mitigation relies on forecasts of plume evolution over time. However, the main sources of uncertainty in plume dispersion modelling remain the accurate quantification of the eruption source parameters, known as ‘source term’, describing the plume characteristics and informing the dispersion models. These parameters include particle size distribution (PSD) and concentrations of ash particles injected into the atmosphere. Estimation of the source term of eruptive plumes by reflectivity measurements using a single frequency radar depends upon assumption of a how PSD and concentrations are combined. The chosen assumptions are however ambiguous as, for example, a high concentration of smaller particles can produce the same reflectivity as that of a low concentration of larger particles. R4AsH is a triple frequency laboratory FMCW radar that simultaneously measures a controlled column of airborne ash at three frequencies: 10, 35 and 94 GHz. Coincident optical measurement of the PSD within the column are also taken to inform analysis. The aim of the R4AsH experiment is to develop a triple-frequency inversion algorithm to enable simultaneous retrieval of the ash PSD and particle concentration by combining radar reflectivity data across the Rayleigh – Mie scattering regime. Following on from our previously reported system design, we will present a review of the radar system performance and preliminary testing for the R4AsH experiments scheduled for the spring/summer of 2022.
高性能毫米波和亚毫米波雷达的支持技术
DOI：
10.23919/irs.2018.8448180
发表时间：
2018
期刊：
2018 19th International Radar Symposium (IRS)
影响因子：
--
作者：
D. Robertson
通讯作者：
D. Robertson
R4AsH：用于表征火山灰落下特征的三频实验室雷达
DOI：
10.1117/12.2587613
发表时间：
2021
期刊：
--
影响因子：
--
作者：
Macfarlane D
通讯作者：
Macfarlane D