Download or read book Effects of Rain Attenuation on Satellite EHF Communications in the United States written by Paul Tattelman and published by . This book was released on 1989 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: One-minute rain rate data over a 10-year period-of-record at each of 41 locations in the contiguous U.S., and for a 6 1/2-year period-of-record at 1 location in Puerto Rico, were extracted from original weighing raingage recordings. The data were analyzed to determine monthly, seasonal, and annual rain-rate frequencies, durations, and probabilities at locations representing a large variety of climatic rainfall regimes. These analyses are particularly useful for estimating EHF (Extremely High Frequency) communication outages due to the increasing effects of attenuation caused by rain at frequencies above 10 GHz. An attenuation model was used to estimate the effects of rain attenuation at all 42 locations. Analyses of the 1-min rain rates, and outage estimates for various frequencies and propagation-path elevation angles are presented.
Download or read book Effects of Rain Attenuation on Satellite EHF Communications in the United States written by Paul Tattelman and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: One-minute rain rate data over a 10-year period-of-record at each of 41 locations in the contiguous U.S., and for a 6 1/2-year period-of-record at 1 location in Puerto Rico, were extracted from original weighing raingage recordings. The data were analyzed to determine monthly, seasonal, and annual rain-rate frequencies, durations, and probabilities at locations representing a large variety of climatic rainfall regimes. These analyses are particularly useful for estimating EHF (Extremely High Frequency) communication outages due to the increasing effects of attenuation caused by rain at frequencies above 10 GHz. An attenuation model was used to estimate the effects of rain attenuation at all 42 locations. Analyses of the 1-min rain rates, and outage estimates for various frequencies and propagation-path elevation angles are presented.
Download or read book Link Availability and Rain Attenuation Exceedance Characteristics for EHF Satellite Communications with Arbitrary Link Parameters in Canada written by S. M. Khanna and published by . This book was released on 1988 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of the Effects of Cloud Attenuation on Satellite Communication Systems written by Tareq A. Alawadi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this project is to investigate the attenuation due to clouds at 20- 50GHz; to develop an accurate long-term prediction model of cloud attenuation applicable to slant-path links and evaluate the impact of cloud attenuation dynamics on the design of future portable EHF earth-space systems. Higher frequencies offer several advantages, for example, greater bandwidth and immunity to ionospheric effects. The EHF band is being targeted for the launch of earth-space communication systems to provide global delivery of bandwidthintensive services (e.g. interactive HDTV, broadband internet access and multimedia services, television receive-only, etc.) to portable terminal units. Since spectrum shortage and terminal bulk currently preclude the realization of these breakthrough-broadband wireless communication services at lower frequencies, a better understanding is needed in order to optimize their usage. One major obstacle in the design of EHF earth-space communication systems is the large and variable signal attenuation in the lower atmosphere, due to a range of mechanisms including attenuation (and scattering) due to clouds and rain, tropospheric scintillation caused by atmospheric turbulence and variable attenuation by atmospheric gasses. In particular, cloud attenuation becomes very significant at EHF. In this thesis, we start with an overview of literature review in the first chapter. Followed next by the theory and description of accepted-up to date- cloud attenuation models in the field (chapter 2). Then followed up by a description of the pre-processing, validations, sources and assumptions made in order to conduct the analysis of the cloud attenuation in this work (chapter 3). Afterwards, a comprehensive analysis of Meteorological and local tropospheric degradation was carried out (chapter 4). That was followed by an overview of cloud fade statistics and suggested methods to counter their effects (chapter 5). And finally the improved cloud attenuation model and the enhancement of the currently accepted cloud attenuation model (ITU-R 840.4) by terms of validating the effective temperature concept and ways of acquiring it (chapter 6).
Download or read book Environmental Research Papers written by and published by . This book was released on with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of the Two component Rain Attenuation Model for Use in Satellite Communication System Design written by Michael A. Kremer and published by . This book was released on 1984 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987-11 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rainfall Effects on Satellite Communications in the K X and C Bands written by Israel Cantor and published by . This book was released on 1972 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: ARCH AND DEVELOPMENT TECHNICAL REPT., Cantor, Israel ;Hudlow, Michael ;DA-1-T-06211-A-1261-T-06211-A-12605ECOM5459(*microwave communications, attenuation), rainfall, radio transmission, k band, x band, c band, communication satellites(active), real time, thunderstorms, meteorological radar, radar signalsan/cps-9, atmospheres, attenuationA survey-type investigation is made into the feasibility of short- and long-term predictions of attenuation and noise temperature fluctuations for satellite communications. The feasibility of using a weather radar, such as the AN/CPS-9, at 9.4 GHz (3.2 cm) for real-time predictions of the above parameters is explored. The suitability of weather radar for such applications is evaluated. Raindrop size data and Mie attenuation theory are used for the derivation of statistical curves that provide attenuation coefficients for various geographic areas and temperatures. (Author).
Download or read book The Dynamic Behavior of Rain Attenuation on Satellite Communication Links written by David Wendell Lee and published by . This book was released on 1983 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Meteorological and Geoastrophysical Abstracts written by and published by . This book was released on 1990 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimates of Satellite EHF Communication Outages Due to Attenuation by Rain written by Paul Tattelman and published by . This book was released on 1987 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides estimates of outage frequencies, durations, and probabilities at eight United States locations for a satellite EHF communication system employing a frequency of 30 GHz and a fade margin of 15 dB. Ten years of 1-min rain rates at each location were used in conjunction with a attenuation model to make the estimates. One-min rates are recognized as most practical for these calculations, but are ordinarily unreadable from original recordings is described. Analyses of the 1-min rain rates and outage estimates for elevation angles of 10 deg, 30 deg, 50 deg, and 70 deg are presented. Keywords include: Rainfall, Attenuation, EHF communications, and Satellite communications.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1989 with total page 1708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of rain attenuation and total atmospheric attenuation for low availability satellite communications written by Seppo Ilmari Karhu and published by . This book was released on 1995 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Services for Family Planning and Infertility United States 1982 written by Gerry E. Hendershot and published by . This book was released on 1988 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1982 statistics on the use of family planning and infertility services presented in this report are preliminary results from Cycle III of the National Survey of Family Growth (NSFG), conducted by the National Center for Health Statistics. Data were collected through personal interviews with a multistage area probability sample of 7969 women aged 15-44. A detailed series of questions was asked to obtain relatively complete estimates of the extent and type of family planning services received. Statistics on family planning services are limited to women who were able to conceive 3 years before the interview date. Overall, 79% of currently mrried nonsterile women reported using some type of family planning service during the previous 3 years. There were no statistically significant differences between white (79%), black (75%) or Hispanic (77%) wives, or between the 2 income groups. The 1982 survey questions were more comprehensive than those of earlier cycles of the survey. The annual rate of visits for family planning services in 1982 was 1077 visits /1000 women. Teenagers had the highest annual visit rate (1581/1000) of any age group for all sources of family planning services combined. Visit rates declined sharply with age from 1447 at ages 15-24 to 479 at ages 35-44. Similar declines with age also were found in the visit rates for white and black women separately. Nevertheless, the annual visit rate for black women (1334/1000) was significantly higher than that for white women (1033). The highest overall visit rate was for black women 15-19 years of age (1867/1000). Nearly 2/3 of all family planning visits were to private medical sources. Teenagers of all races had higher family planning service visit rates to clinics than to private medical sources, as did black women age 15-24. White women age 20 and older had higher visit rates to private medical services than to clinics. Never married women had higher visit rates to clinics than currently or formerly married women. Data were also collected in 1982 on use of medical services for infertility by women who had difficulty in conceiving or carrying a pregnancy to term. About 1 million ever married women had 1 or more infertility visits in the 12 months before the interview. During the 3 years before interview, about 1.9 million women had infertility visits. For all ever married women, as well as for white and black women separately, infertility services were more likely to be secured from private medical sources than from clinics. The survey design, reliability of the estimates and the terms used are explained in the technical notes.
Download or read book Proceedings written by and published by . This book was released on 1995 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:
