Variability and trends in rain height retrieved from GPM and implications on rain-induced attenuation over Nigeria

Abstract

To meet the rising demand for uninterrupted high-speed broadband internet services, the deployment of high-frequency bands for the transmission of radio signals is inevitable. Unfortunately, attenuation due to rain droplets remains the most challenging factor impeding effective radio wave propagation especially in earth-space satellite links operating at Ka and V bands. It is important to understand the attenuation and the parameters that determine its magnitude in order to provide an effective solution to this problem. Rain height as one of the attenuation input parameters was examined in detail. A study of its temporal evolution reveals that seasonal variation is insignificant while the spatial variation shows that it increases from the Sahel to the Coastal Zone of Nigeria. The work provides comprehensive rain height and rain-induced attenuation contour maps. These maps are expected to serve as a database for link budget calculations for different areas in Nigeria. Rain-induced attenuation maps for 1%, 0.1%, and 0.01% of time exceedance are provided at 20 GHz and 40 GHz for Ka and V band signals respectively.

Keywords

• Rain height
• Rain-induced attenuation
• Temporal evolution
• Ka-V band
• Tropical region