System-induced depolarisation of single-polarised satellite beacon signals can be cancelled with vector cancellation. It is demonstrated that the residual error after application of this bias removal technique depends only on the polarisation tilt angle and the XPD of the satellite antenna. It appears that for the calculation of the atmospheric-induced differential attenuation A and phase shift β, correction of the systeminduced differential phase shift for the copolar and crosspolar signals is necessary. An experiment is described to measure this system-induced differential phase shift. It is demonstrated that it is possible to clearly distinguish between rain and ice depolarisation by looking at the scatterplots of the calculated A and β against measured copolar attenuation.
- Data processing
- Satellite links