25-10-2014, 12:15 PM
Abstracts: Satellite undergoes an extensive ground validation test program to ensure in orbit reliability and performance in space. The payload performance and antenna RF characterization of communication satellite on ground is carried out in CATF (Compact Antennae Test Facility). The measurement includes radiation pattern, gain and cross polarization of satellite reflectors. The satellite reflectors are deployed during antenna measurements in CATF. A problem common to deployable reflectors related to space-related projects is that of providing in-orbit realistic environment for testing on earth. During testing on Earth, the structural behavior of antenna is altered by the effect of earth’s gravity. A zero (micro) gravity environment is needed to test such space hardwires in facilities at earth, while a low-gravity environment is needed for lunar simulation. Any error in zero gravity simulation during CATF test results in large error to measurement. Hence, suitable gravity compensation system is required to satellite antenna for ground tests. Gravity compensation systems such as helium balloon method, mechanical method using Zero-G fixture, pneumatic systems comprising thrust, journal and linear air bearings are developed and used for satellite antenna measurements in CATF