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Proceedings ArticleDOI

Application of synthetic storm technique to predict time series of rain attenuation from rain rate measurement for a tropical location

TL;DR: In this paper, a comparison of measured attenuation series with the attenuation obtained from rain rate measurement by using synthetic storm technique is made for Ku band signal at a tropical location.
Abstract: A comparison of measured attenuation series with the attenuation series obtained from rain rate measurement by using synthetic storm technique is made for Ku band signal at a tropical location. Validity of the model is tested for the long-term statistics — the cumulative distribution of attenuation occurrence and fade duration. Applicability of the model is also shown on event by event basis for the present location. The mean absolute error is within 1 dB. It has been shown that the long term statistics of predicted rain attenuation is insensitive to storm translation speed. No significant differences are found when cumulative distributions of predicted attenuation values are compared for different data sampling interval. It has been observed that for 80% events cross corelation coefficient is above 0.85 at zero lag.
Citations
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Journal ArticleDOI
01 Jun 2022-Sensors
TL;DR: In this article , the authors introduced the basic principle and the revolution of CML-based rainfall measurement, and illustrated different steps of signal process in CMLbased rainfall measurements, reviewing the state of the art solutions in each step.
Abstract: As one of the most critical elements in the hydrological cycle, real-time and accurate rainfall measurement is of great significance to flood and drought disaster risk assessment and early warning. Using commercial microwave links (CMLs) to conduct rainfall measure is a promising solution due to the advantages of high spatial resolution, low implementation cost, near-surface measurement, and so on. However, because of the temporal and spatial dynamics of rainfall and the atmospheric influence, it is necessary to go through complicated signal processing steps from signal attenuation analysis of a CML to rainfall map. This article first introduces the basic principle and the revolution of CML-based rainfall measurement. Then, the article illustrates different steps of signal process in CML-based rainfall measurement, reviewing the state of the art solutions in each step. In addition, uncertainties and errors involved in each step of signal process as well as their impacts on the accuracy of rainfall measurement are analyzed. Moreover, the article also discusses how machine learning technologies facilitate CML-based rainfall measurement. Additionally, the applications of CML in monitoring phenomena other than rain and the hydrological simulation are summarized. Finally, the challenges and future directions are discussed.

4 citations

Journal ArticleDOI
TL;DR: In this paper , the global Synthetic Storm Technique (referred to as the global SST) was updated by reformulating it according to a larger database of rain rate time series collected in several sites in different climatic regions.
Abstract: We have updated the global Synthetic Storm Technique (referred to as the global SST) by reformulating it according to a larger database of rain rate time series collected in several sites in different climatic regions. For each site, the average annual probability distribution of rain attenuation obtained with the global SST, PSST,gloA, in a slant path, was compared with that given by the full SST, PSSTA, which we have considered as experimental data. The test was performed for frequency ranging from 10 to 100 GHz, for elevation angle θ ranging from 20° to 60° and for annual probabilities 10% to 0.01%. The global SST tends to underestimate the attenuation by approximately 10% for elevation angle θ≤30° and about 20% for 30°<θ<60° in the probability range 10% to 0.1%, and approximately 15% in the probability range 0.1% to 0.01%. For any probability, the error is zero for θ=90° because at the zenith, the global SST coincides with the full SST.
References
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Journal ArticleDOI
TL;DR: In this article, a physical-mathematical model of the dynamics of rain attenuation was developed and discussed, and the model was tested against the probability distributions of rain long-term 11.6GHz attenuation collected at the three Italian stations (Fucino, Gera Lario, and Spino d'Adda) during the SIRIO propagation experiment (13 years of data) for which concurrent rain rate time series are available.
Abstract: We have developed and discussed the theory and applications of a physical-mathematical model of the dynamics of rain attenuation and have tested it as a rain attenuation prediction model in slant paths. Other parameters, however, such as fade durations and rates of change of fades, can be calculated. The main physical input is the 1-min rain rate time series of a site, which is converted to a rain rate space series along horizontal or slant paths by using an estimate of the storm translation speed v method known as “synthetic storm technique.” However, the long-term predictions are found to be insensitive to v. The vertical structure of precipitation is modeled with two layers. The model was tested against the probability distributions of rain long-term 11.6-GHz attenuation collected at the three Italian stations (Fucino, Gera Lario, and Spino d'Adda) during the SIRIO propagation experiment (13 years of data) for which concurrent rain rate time series are available. In the outage probability range 10−1 to 5×10−3% defined the prediction error e = ( Ap − Am) / Am (where Am and Ap are respectively, the measured and predicted rain attenuations, dB), = −10.6%, σ=7.6% and rms=13%. Compared to nine other well-known prediction methods, the present model surmounts all of them in the three sites tested.

162 citations


"Application of synthetic storm tech..." refers background or methods in this paper

  • ...According to [1] the height above sea level, HA, of the upper limit of layer A is given by:...

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  • ...So far, validity of the SST model is presented in terms of yearly cumulative distribution [1]-[4]....

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  • ...layers [1], layer A with raindrops at 20° C and layer B with...

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  • ...SST has been proposed in [1] to convert instantaneous rain rate into attenuation under some assumption....

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  • ...The physical and mathematical fundamentals of the method are described in [1]....

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Journal ArticleDOI
TL;DR: In this article, the prediction of long-term fade duration statistics in slant paths, obtained from rain attenuation time series simulated with the synthetic storm technique (with input from 1-min rain rate time series).
Abstract: The paper discusses the prediction of long-term fade duration statistics in slant paths, obtained from rain attenuation time series simulated with the synthetic storm technique (with input from 1-min rain rate time series). The results of the prediction were tested against the experimental fade duration statistics collected at three sites of the Sirio experiment in Italy at 11.6 GHz. Predicted and measured statistics are very similar for fade durations longer than about 64–128 s, which represent a fundamental lower limit to fade duration prediction using 1-min rain rate time series. The short durations have not been reproduced because they are mainly caused by tropospheric turbulence, not by the space-time structure of rain, well described statistically by the synthetic storm technique. The prediction is not sensitive to rainstorm speed.

88 citations

01 Oct 1981

52 citations


"Application of synthetic storm tech..." refers methods in this paper

  • ...5 ) sin( = − = θ S B B H H L Km The parameters k and necessary to relate rainfall rate to the specific rain attenuation (dB/Km) are calculated from [9]....

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Journal ArticleDOI
TL;DR: In this paper, the authors used the measurements collected at Spino d'Adda of Italsat 18.7-GHz beacon in a 37.7/spl deg/slant path, and the independent predictions of the synthetic storm technique (SST) for the same radio link, to search the most reliable long term complementary distribution function (CDF) of the slant path.
Abstract: Many prediction methods of long term complementary distribution function (CDF) of rain attenuation based on rain intensity CDF, when tested against concurrent beacon measurements show very similar large errors. In our opinion, these tests may indicate that the real concurrency of rain attenuation and rain intensity CDFs is not sure. The scope of the paper is to show that this can happen even in a well designed and controlled experiment. To this end, we have used the measurements collected at Spino d'Adda of Italsat 18.7-GHz beacon in a 37.7/spl deg/ slant path, and the independent predictions of the synthetic storm technique (SST) for the same radio link, to search the most reliable long term rain attenuation CDF of the slant path, that we found given by the SST CDF. Since the search is based on concurrent and independent rain intensity measurements, we think that our conclusion is sound. We have also discussed how to complete, statistically, a rain attenuation data bank with the SST prediction (such as the large and valuable Italsat data bank) to provide a secure experimental set of concurrent rain attenuation and rain intensity statistics to test prediction methods under controlled conditions, like in a laboratory.

51 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented the first long term simulated annual/seasonal and diurnal rain attenuation statistics, at 12 GHz for a hypothetical downlink from Hellas Sat 2 to Athens.
Abstract: We present annual/seasonal rainfall rate statistics derived from a 29-month data bank of 1 sample/min, measured by a disdrometer located inside the National Technical University of Athens Campus. We discuss both the inaccuracy and the unavailability of the measuring equipment, as well as the statistical reliability of the rainfall rate sample. Additionally, after applying the Synthetic Storm Technique on the measured rainfall rate time series, we present the first long term simulated annual/seasonal and diurnal rain attenuation statistics, at 12 GHz for a hypothetical downlink from Hellas Sat 2 to Athens. According to the results, we predict that communication downlinks working in the afternoon and early evening hours must be given an extra power margin, to compensate for high rain attenuation

36 citations