Development and Flight Testing of an Onboard Video System for the KSLV-I

Abstract

Korea Space Launch Vehicle-I (KSLV-I) carrying the STSAT-2A satellite, made its maiden flight on August 25, 2009. Liftoff was from the Korea Aerospace Research Institute (KARI) launch site at the Naro Space Center in a southern coastal province of the Korean peninsula. A video telemetry system provided visual monitoring of flight critical events, as well as dynamic moving images, through two cameras equipped on the upper stage. This paper describes the development of the onboard video system consisting of two video cameras, a video compression unit and an RF transmitter meeting the requirements of the KSLV-I launch vehicle. During the flight, the ETTARS, an especially reconstructed small telemetry ground station for the KSLV-I, received the video telemetry data and simultaneously measured automatic gain control (AGC) signal levels from the receiver. The onboard video system achieved a 15fps video rate, flew with a 2Mbps data rate and transmitted data using NRZ-L PCM/FM in the S-band. Errors on real telemetry channels occurred as predicted by link budget equations based on thermal noise and multipath interference. According to error analysis, the BER versus SNR performance degradation from the laboratory reference was about 1dB, which is close to expected limit.