Study of slant path attenuation ratios derived from a dual-polarized radar

The use of communication satellites operating above 10 GHz has prompted research on the attenuating effects of rain on these signals. Frequency scaling, a technique where attenuation at one frequency can be scaled up (or down) to another frequency, can extend the known data base of propagation impairments.

This thesis studies the ratios of attenuations in frequency pairs 14/11, 30/20, 30/11, and 20/14 GHz. The attenuation data were derived from a year-long propagation experiment which used a dual-polarized radar to estimate drop size distributions on a slant path between Blacksburg, Virginia, and the Intelsat VA F10 satellite. The effect of varying drop size distributions on attenuation ratios is discussed.

An uplink power control simulation is developed using the attenuation ratios. Attenuation on the uplink path is estimated by scaling the measured downlink attenuation by the appropriate attenuation ratio. The evidence suggests that an uplink power control scheme using drop size distribution-based attenuation ratios offers improvement in satellite link reliability during rain storms.