Diversity reception of COMSTAR satellite 19/29‐GHz beacons with the Tampa Triad, 1978–1981

Abstract

Tampa, Florida (28°N, 82.5°W), has about 90 thunderstorm days per year, almost all in summer. These convective events tend to occur in afternoon or early evening. This paper presents results of 19‐GHz downlink rain attenuation diversity studies in Tampa involving site separations of 11, 16, and 20 km and reception at high elevation angle (about 57°), over a period of 29 months, including three rainy seasons. Almost identical long‐term performance with the two larger spacings indicates that for separations above about 15 km, diversity improvement was not sensitive to baseline orientation or length. During a fourth rainy season, using the remaining 29‐GHz beacon, diversity improvement with the 16‐km pair was similar to that predicted by scaling the 19‐GHz results of the previous seasons. Also discussed are the type of attenuation distributions and typical fade durations to be found under persistent convective conditions. For rain climates like Tampa's, site diversity in some form will be required for high‐reliability SHF satellite links. The diversity data may be helpful in designing schemes for resource sharing among numbers of links.

Multidimensional Rain Attenuation Stochastic Dynamic Modeling: Application to Earth–Space Diversity Systems

“…Test case E refers to a triple-site diversity scheme located in Tampa, FL [29], [30]. The three Earth stations are located in a star scheme with distances 11, 16, and 20 km, respectively [30].…”

Analysis of the interference due to differential rain attenuation induced by an adjacent path on a triple-site diversity Earth-space system

“…In addition, and are the lognormal statistical parameters of the attenuations , , or given by 1 The PASCAL code concerning the numerical calculation of the multidimensional integrals can be obtained by sending a request to the first author by e-mail at chvazour@cc.ece.ntua.gr. in terms of the point rainfall parameters , the constants and of the specific attenuation and the factors , which have the form for for (39) and , are characteristic parameters depending on the spatial structure of the rainfall medium [see also (15)].…”

“…In this band of frequencies, how-0018-926X/99$10.00 © 1999 IEEE ever, attenuation caused by rain is a basic limiting factor affecting the performance of these systems, especially in heavy rain climatic regions, e.g., climatic zones , , , , , , , . In such conditions and considering very large availability time specifications, the site-diversity configuration has been introduced as a mitigation technique to reduce the required large fade margins [1]- [5]. In some severe cases such as operation in the band (30/20 GHz), the link margins result very large and consequently the double-site diversity protection can be proved to be inadequate leading to the employment of triple-site diversity [1].…”

“…In such conditions and considering very large availability time specifications, the site-diversity configuration has been introduced as a mitigation technique to reduce the required large fade margins [1]- [5]. In some severe cases such as operation in the band (30/20 GHz), the link margins result very large and consequently the double-site diversity protection can be proved to be inadequate leading to the employment of triple-site diversity [1]. This is more evident for earth-space paths located in subtropical/tropical regions where the imperative need for reliable transmission with low fade margins, as stated above, seems to impose the inevitable use of triple-site configuration.…”

Three-Site Diversity at Ka-Band Satellite Links in Norway: Gain, Fade Duration, and the Impact of Switching Schemes

“…The ITU-R model [3], as well as multiple measurements [4][5][6][7][8][9] shows that at Ka-band frequencies site separations of a few tens of kilometers can lead to significant reduction of the attenuation. However, both the ITU-R model and majority of the measurements deal only with first order statistics based on ideal selection-combining diversity.…”