Pillai, Sreelal Sreedharan; Sankarattil, Sreekumar; Padmanabhan, Padma; Rao, Vinod Padmanabha; Pillai, Sivasubramonia; Pillai, Madaswamy; Kollamparambil, Damodaran; Kurian, Thomas; Thirunavukkarasu, Chidambaram; Indian Space Research Organization (International Foundation for Telemetering, 2006-10)
      We describe the design and development of a baseband telemetry system for multistage launch vehicles. The system is organized as a three tier one with remote data acquisition and processing units and a centralized control unit. The front-end Data Acquisition Units (DAUs) feature software programmable amplification, offset, filtering and sensor excitation and thus are flexible to interface directly to a variety of sensors used in launch vehicles. The Data Processing Units (DPUs) gather data from DAUs through a serial link compatible to RS-485 standards and carry out a variety of data analysis and data compression functions on selected channels under software control. The central Telemetry Control Unit (TCU) receives this data through a transformer isolated link compatible to MIL-1553B standards and performs the functions of data delay, data storage, onboard computer data monitoring, PCM formatting and pre-modulation signal conditioning to achieve miniaturization. The configuration and features of this telemetry system make its integration simple without compromising on data integrity and reliability and suit the adoption of futuristic technologies and concepts such as smart sensor networks, adaptability, reconfiguration and vehicle health management.