The impact of ice along satellite‐to‐earth paths on 11‐GHz depolarization statistics

Abstract

This paper summarizes measurements of ice depolarization made using a unique facility consisting of a dual‐site (7.3‐km site spacing), dual‐circularly polarized, low‐elevation angle (10.7°) receiving system for the SIRIO 11.6‐GHz beacon. Significant depolarization (cross‐polar discrimination as low as 10 dB) in the absence of attenuation occurred relatively frequently. However, the impact of the ice on the cross‐polar discrimination statistics for a 6‐month time period was small.

Attenuation and Depolarization on Low Angle and Site Diversity Slant Paths

“…4,5) Thus, a modeling technique such as SIM can provide useful predictions of XPD statistics when only attenuation data is available. Figures 6 and 7 do not provide the data needed to predict the degradation of a dual polarized communication link.…”

Prediction of rain effects on earth‐space communication links operating in the 10 to 35 GHZ frequency range

“…Thus, propagation effects on a pair of channels are quantified with attenuation and cross-polarization discrimination values. These are usually expressed in decibel form as A = 20log(a) = 1 0 l o g ( l /~T~l~) ( l l a ) and XPD = 20 log (xpd) = 10 log (~T , ' , /~T~l~) (llb) Equation ( l l a ) follows from ( 5 ) with ITll[ = 1 based on the assumption of orthogonally polarized antennas. The prediction problem is now reduced to evaluating [T'].…”

Calculation of ice depolarization on satellite radio paths

“…In Figure 1 we present calculations for parameter values appropriate to the SIRIO satellite experiment performed at Virginia Polytechnic Institute and State University with a frequency of 11.6 GHz, right-hand circular polarization, and a 10.7 ø elevation angle [Stutzman et al, 1983]. XPD is plotted as a function of the mean azimuth angle of the ice needles for an ice content of 0.002 and with P (the fraction of ice plates) as a parameter.…”

“…Chu [1980] has proposed degrading the normal prediction of cross-polar discrimination (XPD) by 2 dB from that predicted by rain alone to account for ice effects. Stutzman et al [1983] concluded from examining measured 11-GHz data that at low elevation angles, ice degrades XPD by at most 2 dB and at high elevation angles there is negligible degradation.…”