Development and comparison of new methods to process satellite beacon data using microwave profiling radiometer measurements - Application to the generation of total attenuation statistics from EUTELSAT HotBird 6 19.7 GHz beacon measurements in Toulouse

In modern information society, it is increasingly important to ensure ubiquitous access to broadband services on a global scale. Remote locations, such as sparsely inhabited areas or remote travel paths (by airplanes, ships etc.) can be covered most efficiently by broadband satellite communication systems. As the satellite transmissions at frequencies below 15 GHz are becoming congested, it will be necessary to use higher frequency bands to provide wide range of broadband communication services. However, signal transmission at Ka and Q/V bands is more sensitive to atmospheric impairments, especially to attenuation due to rain, which severely affect link availability. This calls for real-time estimation and possibly short- term prediction of such impairments, so that they can be counteracted by appropriate mitigation techniques. In order to enable the design of advanced fade mitigation techniques over a wide satellite coverage area, a multidimensional channel modelling is required (i.e. joint distributions of propagation parameters in space, time and frequency). For improved accuracy and geographical expansion of the model, a coordinated set of measurements is required on a wide scale, comprising several measurement locations. To achieve this goal, various actions have to be taken at different levels, i.e. organization and coordination among various sites, development of efficient common software procedures for data processing etc. A project has been initiated by ESA to design a common ground propagation terminal, meeting scientific and budgetary requirements and enabling comparable observations [1] which is intended to be used in the Alphasat mission, carrying Q/V-band payload (denoted as TDP#5 – Technology Demonstration Payload 5) [2]. At the level of software design, actions are being taken towards the development of a common data processing tool. At previous COST meeting, an example of such a tool has been presented [3]. The goal is to obtain a software package, which will embrace the state of the art procedures for processing the measured data, thus increasing the reliability of obtained statistical data, while its usage has to remain user friendly, possibly by increasing the application of standalone automatic procedures. In this paper, an implementation of efficient procedure for detecting scattering effects is presented. Such a procedure is required in order to adequately combine beacon receiver and radiometer measured data. The proposed procedure is based on searching for linear and nonlinear part of the brightness temperatures scatter plot. In comparison to previous methods, the advantages of the proposed procedure are increased accuracy of obtained statistical data, its automatic adaptability to various conditions of the environment (e.g. different climate zones) and its simple usage, which requires minimal user interaction. The work has been conducted mainly at ONERA, in collaboration with Politecnico di Milano, CNES, ESA and Jozef Stefan Institute.