Over the last years a number of operators have been deploying satellite-based consumer internet access services to reduce the digital divide and capture the market of households not covered by ADSL, cable or wireless broadband. These operators are proposing a step change improvement in the economics of consumer service, with lower terminal costs, broadband access with monthly fees comparable to...

A new dual-frequency (Ku and Ka band) nadir-pointing Doppler radar on the high-altitude NASA ER-2 aircraft, called the High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP), has collected data over severe thunderstorms in Oklahoma and Kansas during the Midlatitude Continental Convective Clouds Experiment (MC3E). The overarching motivation for this study is to understand the behavior of...

The global allocation of L-band, as well as the S-band spectrum, for mobile satellite services represents one of the major strengths for system design that can be utilised by the Inmarsat industry today. However, L-band is now about to be saturated with traffic, and there is a clear trend towards offering more bandwidth demanding services to mobile satellite terminals as well, including video, ...

The effects of satellite diversity on Ka-band rain attenuation were investigated in three propagation paths with azimuth angle separation of about 30 deg in Japan. The Ku-band (14/12 GHz) attenuation was converted to the Ka-band down-link (19.45 GHz) attenuation by the frequency scaling methods considering the difference of raindrop size distributions. As for the attenuation of 20 dB, time perc...

Since the designation in the 1970’s of a military satellite communications Ku-band (30-31 GHz uplink, 20.2-21.2 GHz downlink), these frequencies have held great potential to support U.S. forces and requirements. In 1995, the Ku band was chosen for the Global Broadcast Service (GBSJ which will be operational on the UFO satellites beginning in 1998. However, only a small percentage of the allocat...

Space-borne X-band synthetic aperture radars (SARs) provide a unique opportunity to measure rainfall over land with unsurpassed spatial resolution of about few hundred meters. This work explores the potential of space-borne X-SARs to estimate rainfall over land from both a model and retrieval point of view. The main objective is to provide a framework for a physically-based inversion of SARs me...

Radars at different frequencies have been used over five decades for observing precipitation. S and C bands have been employed for long range coverage observations. Dual-polarization X-band radars have been shown to be useful for networked applications. Space borne precipitation radars have been at Ku band, or higher frequencies such as Ka, as in the GPM mission. This paper presents a comprehen...