Thiyagarajan Beeman, National Centre for Radio Astrophysics, Pune, India
Shailendra Bagde, National Centre for Radio Astrophysics, Pune, India
Dr. Bhal Chandra Joshi, National Centre for Radio Astrophysics, Pune, India

The Giant Metrewave Radio Telescope (GMRT), located near Pune, India, consisting of 30 fully steerable parabolic dishes of 45m diameter each, provides the facility for frontline research in radio astronomy. The GMRT servo system is a dual drive closed loop position feedback control system for accurately tracking and positioning of the GMRT radio telescopes to celestial objects. The next generation digital controller for GMRT antennas is built with more powerful and highly sophisticated state-of-the-art industry standard PC104 Single Board Computer (PC104 SBC) with Linux-Real Time Application Interface (RTAI) operating system.  In this paper, we present the design details of developed RTAI based hard real time embedded system for GMRT antennas and its significance in control of a radio telescope as well as we present the various hardware features of the GMRT servo system, architecture of the antenna control software and additional advantages of the upgraded servo system. We also present various performance indices of RTAI system, performance of the servo system in terms of tracking and positioning accuracy.