scispace - formally typeset
Search or ask a question
Book

Electromagnetic Wave Propagation Through Rain

08 Feb 1996-
TL;DR: In this article, the effects of rain on weather and climate models are discussed, and an approach to attenuation mitigation via diversity via diversity is proposed. But this approach is not suitable for outdoor environments.
Abstract: Effects of Rain. Rain Structure and Rain--Rate Statistics. Rain--Rate Climate Models. Modeling Attenuation by Rain. Attenuation Mitigation via Diversity. Worst--Month Statistics. Estimating Risk. References. Appendix. Index.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, tools for the prediction of rain rate and rain attenuation are presented in the form of contour maps for Nigeria using a massive rainfall data bank of 30 years which are taken from measurements made from the coast to the arid region of Nigeria.
Abstract: Rain rate and rain attenuation predictions are one of the vital steps to be considered when analyzing a microwave satellite communication links at the Ku and Ka bands. In this paper, tools for the prediction of rain rate and rain attenuation are presented in the form of contour maps for Nigeria using a massive rainfall data bank of 30 years which are taken from measurements made from the coast to the arid region of Nigeria. Rain-rate maps for the country of Nigeria were developed using the models purposely designed for tropical zones while ITU-R models were used for the rain-attenuation maps. The information from these maps will be a good preliminary design tools for both terrestrial and earth-satellite microwave links and also provide a broad idea of rain attenuation for microwave engineers

146 citations


Cites result from "Electromagnetic Wave Propagation Th..."

  • ...…of rain-rate and rain-attenuation has naturally attracted a great deal of attention — for instance this kind of work has earlier been carried out for USA [12], Europe [12, 14,Gunes et al., 1994], Malaysia [3], Colombia [13] and on global scale by ITUR [10], Salonen and Baptisa [16], Crane, 1996....

    [...]

Journal ArticleDOI
TL;DR: The objective of the research was to determine multipath and time varying channel behavior of short-hop millimeter-wave point-to-multipoint radio links during various weather events, and a novel prediction technique is presented that applies canonical antenna patterns and site specific information to estimate worst case multipath channel characteristics.
Abstract: This article presents results of a wide-band measurement campaign conducted at 38 GHz. The objective of the research was to determine multipath and time varying channel behavior of short-hop millimeter-wave point-to-multipoint radio links during various weather events. 73963 power delay profiles (PDPs) were captured on three links, each comparable to proposed local multipoint distribution systems (LMDS) in a campus environment. Multipath was observed in unobstructed LOS links during rain but not during clear weather. Short-term variation of the received signal over 1-2 min observation periods is described by a Rician distribution with a K factor which varies as a function of rain rate. Measured rain attenuation exceeds Crane's (1996) model predictions by several decibels. A novel prediction technique is presented that applies canonical antenna patterns and site specific information to estimate worst case multipath channel characteristics including relative power, time of arrival (TOA), and angle of arrival (AOA) of each multipath component. New metrics, the excess delay zone and relative power zone, are defined and contour plots are developed to determine potential reflectors from an area site map. These results and models provide useful guidelines for the design of millimeter-wave wireless communication systems.

129 citations


Cites background from "Electromagnetic Wave Propagation Th..."

  • ...I. INTRODUCTION T HE INCREASING demand for broadband multimediacommunications coupled with new millimeter-wave spectrum issued by governments throughout the world has motivated extensive research in new wireless services such as local multipoint distribution systems (LMDS), mobile broadband systems…...

    [...]

31 Dec 1998

116 citations


Cites background from "Electromagnetic Wave Propagation Th..."

  • ...Crane (1996) gives an extended overview of the statistics and structure of rain....

    [...]

Journal ArticleDOI
TL;DR: In this article, a stochastic-dynamic model for the planning and design of gigahertz satellite communications using fade mitigation techniques is presented, which is a generalization of the Maseng-Bakken and targets dualsite dual-frequency rain attenuated satellite links.
Abstract: We present a new stochastic-dynamic model useful for the planning and design of gigahertz satellite communications using fade mitigation techniques. It is a generalization of the Maseng-Bakken and targets dual-site dual-frequency rain attenuated satellite links. The outcome is a consistent and comprehensive model capable of yielding theoretical descriptions of: 1) long-term power spectral density of rain attenuation; 2) rain fade slope; 3) rain frequency scaling factor; 4) site diversity; and 5) fade duration statistics using a novel method based on Markov Chains. We also present a simple rain attenuation synthesizer matching the predictions of the theoretical model.

109 citations


Cites background from "Electromagnetic Wave Propagation Th..."

  • ...A logical extension is that the distribution of rainrate at two points on the horizontal plane is jointly lognormal [21] with probability density function (pdf) given by (1) at the bottom of the next page, where and are the point rainfall rates (millimeter/hour) for the two locations 1 and 2, respectively, of interest and is the cross-correlation factor between and ....

    [...]

  • ...It is also inspired from the seminal works in [19]–[21] which to a lesser extent attempted to achieve very similar objectives....

    [...]

Journal ArticleDOI
TL;DR: By acquiring simultaneous weather-radar data over the test site and the SAR acquisition, it was possible to flag affected SAR images and to exclude them from the procedure to derive the absolute calibration constant, and to decrease the 1 sigma uncertainty of theabsolute calibration factor by 0.15 dB.
Abstract: TerraSAR-X, the first civil German synthetic aperture radar (SAR) satellite, was successfully launched on June 15, 2007. After 4.5 days, the first processed image was obtained. The overall quality of the image was outstanding; however, suspicious features could be identified which showed precipitation-related signatures. These rain-cell signatures are thoroughly investigated, and the physical background of the related propagation effects is provided. In addition, rain-cell signatures from former missions like SIR-C/X and the Shuttle Radar Topography Mission are provided for comparison. During the commissioning phase of TerraSAR-X, a total of 12 000 scenes were investigated for potential propagation effects, and about 100 scenes revealed atmospheric effects to a visible extent. Some of the particularly interesting events were selected and are discussed in greater detail. An interesting case of data acquisition over New York will be presented, which shows typical rain-cell signatures, and the SAR image will be compared with weather-radar data acquired nearly simultaneously (within the same minute). By comparing the images, it can be clearly seen that reflectivities in the weather-radar image of 50 dBZ may cause visible artifacts in SAR images. Furthermore, in this paper, we discuss the influence of the atmosphere (troposphere) on the external calibration of TerraSAR-X. By acquiring simultaneous weather-radar data over the test site and the SAR acquisition, it was possible to flag affected SAR images and to exclude them from the procedure to derive the absolute calibration constant. Thus, it was possible to decrease the 1 sigma uncertainty of the absolute calibration factor by 0.15 dB.

96 citations


Cites background or methods from "Electromagnetic Wave Propagation Th..."

  • ...For the statistical computation, we have used a model provided in [14], which allows the estimation of the annual probability of attenuation as a function of several parameters....

    [...]

  • ...Attenuation by snow, fog, and gases can be found in more detail in [9], [11]–[14]....

    [...]

  • ...After [14], the two-way attenuation for a given instant of time can be obtained by integrating the specific attenuation along the path of propagation using the following expression:...

    [...]

  • ...between specific attenuation γ(x, t) and rain rate R is provided [14], [17], [18]....

    [...]