• Paradigms Optimization for a C-Band COFDM Telemetry with High Bit Efficiency

      Skrzypczak, Alexandre; Thomas, Alain; Duponchel, Guillaume; Zodiac Data Systems (International Foundation for Telemetering, 2013-10)
      Systems using single carrier modulations for flight test transmissions perfectly fit noisy and time selective channels. However, the densification of the airport environment now makes the aero channel also frequency selective due to multiple reflections on surrounding buildings, especially while taxiing and taking off. Obviously, this has a direct consequence on hardware resources and user data rates. In such a context, COFDM represents an appealing solution thanks to its inherent robustness to multipath fading channels. But a direct application of an off-the-shelf COFDM standard is not straightforward as these standards are designed for specific channels whose characteristics are quite different from the aero one. That is why we made an experiment at Toulouse-Blagnac airport to jointly sound the channel and qualify a COFDM waveform. This paper then describes the construction of the waveform and the results of the channel sounding. From this, different standard paradigms are compared.
    • PCM Telemetry Downlink for IRIG 106 Chapter 10 Data

      Pappas, Johnny; Bagó, Balázs; Cranley, Nikki; Poisson, Gabriel; Zodiac Data Systems (International Foundation for Telemetering, 2013-10)
      Since both airborne and ground applications are able to handle and process IRIG 106, Chapter 10 standard data (further referred to as C10) from files or from live streaming UDP network data, it is a logical extension of the standard to telemeter network data from the air to the ground support systems with little or no modification. This paper describes a method to transport C10 compliant packets over a Class II, telemetry stream (C10 TMDL) which is fully compatible with existing encryptors, transmitters, receivers, and decryptors.
    • PTPV1 and PTPV2 Translation in FTI Systems

      Lefevre, D.; Cranley, N.; Holmeide, Ø.; Zodiac Data Systems; Ontime Networks AS (International Foundation for Telemetering, 2013-10)
      A Flight Test Instrumentation (FTI) system may consist of equipment that either supports PTPv1 (IEEE 1588 Std 2002) or PTPv2 (IEEE 1588 Std 2008). The challenge in such time distributed system is the poor compatibility between the two PTP protocol versions. This paper describes how to combine the PTP versions in the same network with minimum or no manual configuration.
    • A Tri-Band L, S, C Prime Focus Feed: Concept, Design and Performance

      Melle, Christophe; Chaimbault, David; Peleau, Fabien; Karas, Alain; Zodiac Data Systems (International Foundation for Telemetering, 2013-10)
      The flight test mission services need higher data rates due to increased system complexity and the need for more accurate, higher rate, and better data acquisition. The existing L or S band frequency spectrum allocation was a limiting factor to meet this increased data rate requirement. The World Radio-communication Conference (WRC 2007) attributed new additional frequency spectrum allocations in the C band for Aeronautical Mobile Telemetry (AMT). The international flight test community has taken this opportunity to immediately take advantage of the new C-band range 5091-5250MHz. This paper presents the multi-band feed product designed by the RF & Antenna Laboratory of ZODIAC DATA SYSTEMS company. This feed is foreseen to be used in prime focus configuration on any diameter parabola dish providing telemetry and tracking channels in three L, S, and C bands. Here, are described the concept and the technology achieved taking into consideration the performance and industrial constraints. Moreover, this contribution focuses on the electromagnetic simulations of radiating elements, the feed network and RF system integration. This paper is structured as follows: firstly, the objectives and the motivation for developing a prime focus feed which works in L, S, C bands are presented. In particular, the market constraints and approach to find the best solution satisfying the feed RF requirements, and mechanical constraints, such as weight, size and cost, are discussed. The second section describes the 5 step development cycle: principle and technology, design of the telemetry channels and tracking function, cohabitation of the different radiating elements, and problems of the channels isolations. The third section discusses the performance achieved using electromagnetic simulations. The fourth section talks about the integration of RF system feed. The paper concludes by discussing future work using the same concept that is applied to other telecommunication or telemetry frequency bands.