نتایج جستجو برای: rain

تعداد نتایج: 17335  

2010
Zhanqing Li Ruiyue Chen

Though warm rain from low-level liquid clouds contributes significantly to the global precipitation and water cycle, it has been missed or underestimated by satellite remote sensing techniques. IR techniques miss all warm rain because they rely on cloud top temperature. Over land, passive microwave techniques miss all warm rain because they rely on ice scattering at high frequency channel. Over...

2005
Animesh Maitra Kaustav Chakravarty

Measurements of rain attenuation over an earth-space path at Kolkata (22°34' N, 88°29' E), India, have been carried out since June 2004 by receiving a Ku-band signal from the satellite NSS-6 (geostationary at 95 E). The instantaneous attenuations are estimated from the point rain rates measured with an optical raingauge and using the Simple Attenuation Model (SAM). The estimated values closely ...

2011
L. S. Kumar Y. H. Lee J. X. Yeo J. T. Ong Cheng Soon Garden

A Z-R relation is derived using a data set which consists of nine rain events selected from Singapore’s drop size distribution. Rain events are separated into convective and stratiform types of rain using two methods: the Gamache-Houze method, a simple threshold technique, and the Atlas-Ulbrich method. In the Atlas-Ulbrich method, the variability of the rain integral parameters R, Z, Nw, D0 and...

2007
R. Posselt U. Lohmann

Prognostic equations for the rain mass mixing ratio and the rain drop number concentration are introduced into the large-scale cloud microphysics parameterization of the ECHAM5 general circulation model (ECHAM5-RAIN). For this a rain flux from one level to the next with the appropriate fall speed is introduced. This maintains rain water in 5 the atmosphere to be available for the next time step...

2001
P. Fiorucci P. La Barbera L. G. Lanza R. Minciardi

A rain field reconstruction and downscaling methodology is presented, which allows suitable integration of large scale rainfall information and rain-gauge measurements at the ground. The former data set is assumed to provide probabilistic indicators that are used to infer the parameters of the probability density function of the stochastic rain process at each pixel site. Rain-gauge measurement...

2017
Mengjiao Jiang

This study evaluated the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) forecast bias in different precipitation (light rain, moderate rain, heavy rain and very heavy rain) by comparing the ground-based observations in three countries. Then the correlations between GFS precipitation forecast errors and the aerosol loading are investigated extensively to examin...

2011
Ruiyue Chen Zhanqing Li Robert J. Kuligowski Ralph Ferraro Fuzhong Weng

[1] Warm rain occurs in low‐level liquid water clouds and does not involve an ice‐phase process. Comprising many state‐of‐the‐art passive and active instruments, the NASA A‐Train series of satellites provide comprehensive simultaneous information about warm clouds and their precipitation processes. This study exploits multi‐sensor data from the A‐Train satellite constellation to investigate the...

2001
Khalil Ahmad W. Linwood Jones Takis Kasparis

Microwave brightness temperatures are obtained from the SeaWinds scatterometer on the QuikSCAT satellite. These QuikSCAT Radiometer (QRad) measurements are used to infer instantaneous oceanic rain rates using a statistical retrieval algorithm that is based upon collocated TMI measurements. QRad instantaneous rain rate measurements have been binned in 0.5 hour local time windows onto a 0.5° x 0....

Journal: :Space Communications 2005
Clemence Alasseur A. Núñez Fernando Pérez-Fontán Lionel Husson U.-C. Fiebig Perfecto Mariño Espiñeira

This paper describes two methods for generating synthetic rain rate time-series capable of being used to simulate the performance of radio communication systems operating above 10 GHz. Rain rates are modelled because they are widely available and because an approximate link to signal attenuation can be established owing to the significant correlation between them. The proposed models are based ...

Journal: :IEEE Access 2021

Image deraining is a low-level restoration task that has become quite popular during the past decades. Although recent data-driven models exhibit promising results, most of these are trained on synthetic rain data sets which do not generalize well when applied to real images. While real-rain have achieved favorable generalization performance, generating rain-free ground-truths can be tedious an...

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