Attenuation of Spruce, Pine, and Deciduous Woodland at C-Band

Abstract

The presence of vegetation in the radio path significantly attenuates centimeter and millimeter radio waves. The attenuation depends on the type of vegetation, its density, the season, and the frequency. Attenuation models exist for the horizontal path through vegetation and the slant foliage path through roadside trees. In this study, slant foliage paths through roadside woodland are investigated. This letter presents results for the slant path attenuation loss at 5.2-GHz C-band frequency at three elevation angles (20 , 40 , and 60 ) and three types of vegetation (spruce, pine, and deciduous woodland). Differences between horizontal and slant path results are discussed, and cumulative distribution statistics of the attenuation in the various vegetation types are given.Index Terms-Attenuation in vegetation, C-band, excess loss, satellite communications, slant foliage path.

A New Model for Scattering From Tree Canopies Based on Physical Optics and Multiple Scattering Theory

“…For the case of a completely transparent object where E aper = −E block , (16) fulf lls that E tot must equal E dir as…”

Rf Propagation Experiments in Agricultural Fields and Gardens for Wireless Sensor Communications

“…From Table 1 and Table 2, it is evident that path loss values are higher in maturity stage than growth stage. This is due to type of vegetation and its density, high crop plant, wide stem diameter and long leaves which tend to increase the path loss in agricultural fields [21]. When considering the case of corn field, 0.6 of the first Fresnel zone radius along the path is less than the antenna height, and hence the vegetation attenuation is mainly caused by free space loss and canopy reflection.…”

“…In addition, the humidity in agricultural fields and gardens is usually much higher than that in other places [22]. The humidity in the vegetation is an important parameter that determines its dielectric properties and, as a consequence, influences radio wave propagation [21]. The relative humidity in tropical climate like Sivanthanpatti village and Kattankulathur, where we have done our experiments can reach as high as 74% (very humid) in a typical August/October day.…”

First-Order Statistics Prediction for a Propagation Channel of Arbitrary Non-Geostationary Satellite Orbits

“…Generally, such models need to be based on available experimental data; however, obtaining suitable experimental data is demanding. It is common to utilize a so-called pseudo-satellite which may be in a form of a transmitter (Tx) placed on a helicopter [9][10][11] or a remote-controlled airship [7], [12], [13], at a crane or the upper-most point in the surroundings for fixed-elevation measurements [14][15][16], or even collect data from an existing satellite [17][18][19].…”

“…Instead, respecting high costs of experimental campaigns when using a pseudosatellite, pre-defined flight paths, such as a star-pattern [7], circle [11], or hemisphere [10], are chosen for selected scenarios.…”