Determination of sky status by ground based radiometric data analysis
| Autor: | M. Maiti, Kausik Bhattacharyya, Anoarul Islam, Salil Kumar Biswas, Ayan Pradhan, Judhajit Sanyal |
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| Rok vydání: | 2021 |
| Předmět: |
Brightness
Multidisciplinary Radiometer media_common.quotation_subject Astrophysics::Instrumentation and Methods for Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Sky Histogram Brightness temperature Extremely high frequency Data analysis Environmental science Astrophysics::Galaxy Astrophysics Microwave Remote sensing media_common |
| Zdroj: | Indian Journal of Science and Technology. 14:2250-2256 |
| ISSN: | 0974-5645 0974-6846 |
| DOI: | 10.17485/ijst/v14i27.447 |
| Popis: | Objectives: To predict meteorological phenomena such as rain events from sky status during rainy and non-rainy periods. Methods: The method used here is based on brightness temperature ratio measurement at two different frequencies, namely 23.8 GHz and 30 GHz respectively, using ground based dual frequency radiometric data. The ratios of brightness temperature readings obtained by the dual-frequency radiometer at the two above mentioned frequencies are calculated for each simultaneously-taken pair of measurements. Data obtained by the authors for the year 2009 at Cachoeira Paulista in Brazil has been used for analysis. Findings: The major results obtained from the analysis of data collected over a continuous period of seven months are used to construct corresponding histograms and cumulative count graphs of brightness temperature ratios. The histograms and graphs clearly show three peak values that could be interpreted as thresholds between clear sky, cloudy sky and rainy sky conditions respectively. Novelty: The study implements detection of rain events from sky status during rainy and non-rainy periods using peak brightness temperature values obtained from graphs generated using the observation data. The outlined technique can therefore be used to clearly determine sky conditions and accurately predict rain phenomena. The ratio of brightness temperatures at the two frequencies is a unique parameter which is critical to the successful estimation of rain from sky status. The results agree well with multi-channel radiometric data obtained by other researchers at lower frequencies. Keywords: sky status; microwave; millimeter wave; dual frequency radiometer; brightness temperature; rainfall |
| Databáze: | OpenAIRE |
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