Design and Concept of Fiber-Optical and I²C Hybrid Sensor Bus System for Telecommunication Satellites

In this paper the design of the Hybrid Sensor Bus(HSB) for telecommunication satellites is presented. In state of the art European telecommunication platforms hundreds of point-to-point wired sensors are necessary for satellite control and monitoring. To reduce the high mass impact of the wiring a modular open-standard bus system consisting of an electric I²C sensor bus and a fiber bragg grating based fiber-optic sensing for thermal mapping is developed. Special attention is given to the fiber optical interrogator module. A trade-off between different designs, based on edge filter and scanning laser concepts is also presented. In the edge filter concept the FBG's are illuminated by a broadband light source, the reflected light is split up in two parts; both paths are analyzed by a photodiode, whereas one part is first fed through an edge filer. In the tunable laser concept the laser light is tuned in wavelength and the backscattered light is analyzed. The advantages and disadvantages of both systems are discussed and taken into account to select the most suitable system.